Lite-On SHW-1635S review

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Introduction:

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Thanks to Lite-On BV for sending the Lite-On SHW-1635S our way. It's a fully featured 16x DVD+/-R DVD-writer that also offers DVD-R Dual layer and DVD+R Double layer writing, so let us see how it performs compared to the competition.

Company Information:

Let us take a look at some of the company information found at the Liteon Website:

Lite-On Technology Corporation's vision is to become a world-class excellent company. The company will accomplish this not only through leading global R&D and manufacturing technologies, but also through the quality and distinctiveness of its products.

To reach these levels of excellence and become the leading navigator in 3C convergence, Lite-On plans to generate between five and six billion US dollars in annual revenue while establishing itself as a global market-leader by mastering all of its product-line industries. The company's ability to generate profits will guide the industrial circles in which it competes. While accomplishing these goals, corporate management will continue its policies of absolute financial transparency, independence, and impartiality.

The company's pursuit of excellence does not end there. To create better lives for people, Lite-On will also continue to develop advanced and integrated digital products while furnishing customers with innovative values that lead to true, beneficial relationships. Lite-On wants to be the best strategic partner for each of its customers.

Led by a professional team with promise and lofty ethics, Lite-On will also strive to be an excellent corporation with peak efficiency. The company will provide shareholders and investors with an appealing return-on-investment. Additionally, Lite-On will supply employees with an optimum work environment that helps them learn new skills and grow professionally for the future. Lite-On seeks to become one of the best corporations that people in greater China can choose for a career.

Facts & Figures:

• Lite-On Technology reported its global consolidated June revenue of NT$13.7B, increasing 4% on a YoY basis.
• Accumulated revenue in 2005 totaled NT$75.6B, growing 2% on a YoY basis.

If you are interested in reading more company information, please visit: Liteon

Drive specifications:

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These are the specifications of this drive, found at the Lite-On webpage:

SHW - 1635S 16x 8x / 16x 6x / 8x 4x / 16x + 48x 24x 48x Half-Height DVD-Dual

• ATAPI / E-IDE Half-Height internal DVD+R / DVD+RW / DVD-R / DVD-RW / DVD+R9 / DVD-R9 / DVD-ROM / CD-R / CD-RW / CD-ROM combination drive
• Support Double Layer DVD +/- R9 Recording Function
• SMART-BURN avoiding Buffer Under Run Error, Automatically adjusting writing strategy & running OPC to provide the best burning quality
• SMART-X function adjusts CD-DA / VCD / DVD data extraction to a fastest allowable speed according to both data request rate from host and disk quality
• VAS® system reduce vibration and noise during recording and reading
• Support Fixed Packet, Variable Packet, TAO, SAO, DAO, Raw Mode Burning & Over-Burn
• DVD read compliant : DVD single/dual layer ( PTP / OTP ), DVD-R ( 3.9 GB / 4.7 GB ), DVD-R multi-borders, DVD+R, DVD+R multi-sessions, DVD-RW, and DVD+RW
• CD read compliant : CD-DA, CD-ROM, CD-ROM / XA, Photo-CD, Multi-session, Karaoke-CD, Video-CD, CD-I FMV, CD Extra, CD Plus, CD-R, and CD-RW
• Supprot both 8 cm and 12 cm disc of CD and DVD family
• Conform to Orange Book : Part 2 CD-R Volume 1, Part 2 CD-R Volume 2 Multi Speed, Part 3 CD-RW Volume 1 ( 1x, 2x, and 4x ), Part 3 CD-RW Volume 2 : High Speed, Part 3 CD-RW Volume 3 : Ultra Speed
• Supported transfer mode: PIO mode 4, DMA mode 2 and Ultra DMA mode 4

DVD Family :	Write	DVD+R	16x ( 21600 KB/sec ) maximum by CAV
		DVD+R9	8x ( 10800 KB/sec ) maximum by Z-CLV
		DVD-R	16x ( 21600 KB/sec ) maximum by CAV
		DVD-R9	4x ( 5400 KB/sec ) maximum by CLV
	ReWrite	DVD+RW	8x ( 10800 KB/sec ) by CLV
		DVD-RW	6x ( 8100 KB/sec ) by CLV
	Read	16x ( 21600 KB/sec ) maximum by CAV
	Access time	160 ms
CD Family :	Write	CD-R	48x ( 7200 KB/sec ) maximum by CAV
	ReWrite	CD-RW	24x ( 3600 KB/sec ) maximum by Z-CLV in UltraSpeed disc
	Read	48x ( 7200 KB/sec ) maximum by CAV
	Access time	160 ms
Buffer Size :	2 MB ( Max )
PC Required :	Pentium 4 1.3 GHz or higher CPU and 128 MB or higher RAM are required
	HDD must have access time < 20 ms; with a minimum of 650 MB free space
	9 GB free space for creating a DVD image file ( 9 GB for double layer; 5 GB for single layer)
Compatibility :	Microsoft Windows 98SE / ME / 2000 / XP
MTBF ( Life ) :	70,000 POH
S/N Ration :	> 75 dB
Environment :	Operating	5C to 45C; Relative Humidity : 15% to 80%
	Non-Operating	-40C to 60C; Relative Humidity : 15% to 95%
Dimension :	145.0 ( W ) x 41.3 ( H ) x 170.0 ( D ) mm
Weight :	< 0.9 Kg
Voltage Requirements :	+5V +/-5% and less than 100 mVp-p ripple voltage
	+12V +/-5% and less than 200 mVp-p ripple voltage

 It can't fully match the DVD-R DL and CD-RW writing speeds of some other drives, but beside this it seems to be pretty good. But let us see if the real world performance is as good as the specifications states.

What's inside the box?

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The drive we received was a retail drive that came in a nice looking box:

No big changes, the main features are clearly shown, and more importantly; it's clear that this drive ships with an additional bezel! That's nice.

The package contents seems to be pretty good too, but let us list everything we got:

⋅        The drive itself
⋅        Extra black front bezel with tool to manually eject the tray, useful when changing bezel.
⋅        Power DVD 5 software CD.
⋅        Nero Express 6.6 software CD.
⋅        4 screws
⋅        Audio cable
⋅        Quick install guide
⋅        Bezel change guide
⋅        Safety notice paper

All in all very good, the extra bezel does add some extra value to many people, but for a perfect bundle, we would like to see some more printed documentation as well as some empty discs.

Now it's time to take a look at the drive itself:

 

Well, here we do see a difference compared to earlier Lite-On drives; the logos on the tray are slightly changed, but more important; the volume knob and headphone connector is removed. The LED is also moved closer to the middle of the drive.

 

Our sample was produced in China and has a production date of July 2005.

 

But on the back, there are no changes; from the left: undocumented pins probably used for calibrating/testing the drive at the factory; digital audio connector; analogue audio connector; pins and jumper to set the drive to cable select, slave or master; IDE connector and finally the power connector.

Now, let us connect the drive and check out the features and program bundle of this drive on the next page…

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Test
machine:

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For this review we will be using a
computer with the following configuration:

Hardware:

• Motherboard: Abit IC-7 MAX3
  i875P
• Processor:
  Intel Pentium 4 3,2GHz 800MHz FSB Prescott with Hyper Threading
  support.
• RAM: 1Gb
  PC4300 DDR
• GFX: Asus
  GeForce 6800
• Sound: SB
  Audigy 2
• Hard disk:
  400Gb Seagate Barracuda 7200.8 S-ATA connected to the Intel i875P S-ATA
  controller.

System set-up:

 

The Lite-On SHW-1635S was
connected as Secondary Master and identified itself as LITE-ON DVDRW SHW-1635S.
DMA (Direct Memory Access) was enabled for all devices
where it was possible.

Software:

Windows XP Professional is
installed on the computer along with Service Pack 2 for Windows XP. We will be
using the following software in this review:

• Nero Burning ROM version 7
• Nero CD-DVD Speed v4.07
• Nero InfoTool v3.0.7
• DVD-Identifier
  4.0.1
• K-Probe v2.5.1

Installation and
supported features:

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We quickly installed the drive
without any problems and here is a screenshot from Nero InfoTool:

 

Our drive came shipped with
firmware YS0G, we updated the firmware to version YS0P/YS0Q for this review.
Later we got YS0R to address some issues we pointed out and thus some tests are
re-done with YS0R. The drawbacks we could see are the inability to read and
write DVD-RAM discs as well as missing Mt. Rainier support along with a slightly
small buffer. A larger buffer would at least smooth up the data transfer to the
drive a bit on stressed systems. Lite-On will release a super-multi drive later
that also supports DVD-RAM.

Book type
changing:

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To see if the
Lite-On SHW-1635S supports bitsetting we tried with Lite-On's official
tool:

 

As we could see, it
supports bitsetting. The write now button is for directly changing the booktype
on a DVD+RW disc. It is also possible to change and save the booktype wanted in
the EEPROM. You could also use the bitsetting feature in KProbe under the tools
menu. Or you could use Nero CD-DVD Speed to change the bitsetting:

Notice that changing
the booktype in Nero CD-DVD speed will not be permanent, so you have to change
it again when you restart your computer. Let us see if booktype changing
actually works:

Yes it sure does, we
could see that book type is listed as DVD-ROM.

Error scanning
of written discs:

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The Lite-On
SHW-1635S supports error reporting just like earlier drives from Lite-On. Here
are two examples of programs you may use for checking your written discs for
errors.

KProbe is developed
by a Lite-On
employee, but it's not an
official Lite-On program. This is what we use in our reviews. But you may also
use Nero CD-DVD-speed:

Nero CD-Speed
is just as good and also gives you an indication of the quality by giving a
score. Higher score is better; a good result should at least be over 80 in
quality score. Nero CD-DVD speed is included with newer Nero 6.x and 7.x
versions or available as a separate download from www.cdspeed2000.com.

Included software:

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Now it's time to
look at the included software, and comment if needed. Notice that we may not use
the included software in our performance testing part of the review.

Power DVD
5:

The drive
includes Power DVD 5 to play DVD and VCD movies. PowerDVD is among our favourites so Lite-On made
a good choice including it.

Nero 6.6 OEM
Suite:

The well-known Nero
suite is also included and covers all tasks from creating the movie to writing
it to the disc. This is one of our favourite programs.

Now that we have finished
examining the drive and bundled programs '“ let us head on to the next page,
which is reading performance test…

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 Reading
performance:

For these tests we will use Nero
CD-DVD-Speed to read various CD and DVD's, including audio discs and DVD-media.
As already mentioned in the introduction, this drive sports a specified read
speed of 16X for DVD's and 48X for CD's.

Pressed
discs:

For this test we used a pressed
CD-ROM disc containing PlexTools v1.08 that is exactly 74 minutes long. Below
you will see the produced result:

 

The Lite-On SHW-1635S had no
problems reaching 48x. To see how this compares to other drives, look
below:

One of the faster readers we have
tested, the seek times is about average compared to other drives.

CD-Recordable
Discs:

For this test we made a copy of
the original PlexTools v1.08 CD. The disc we used was a Verbatim 48X certified
CD-R disc manufactured by Mitsubishi Chemicals Corporation.

 

No big differences compared to
reading the original pressed disc, but let us compare the result to some other
drives:

It was able to beat all the other
drives, but the difference is rather small. Seek times are again average
compared to the other drives.

CD-ReWritable
discs:

Again we made a copy of the
original PlexTools v1.08 disc, this time we used a Verbatim High Speed (10X)
CD-RW disc made by Mitsubishi Chemicals Corporation.

 

The Lite-On SHW-1635S reads CD-RW
discs at 32x speed only. Check how this compares to other drives
below.

Among the slower drives due to the
low reading speed, we would like to see an improvement on this. But the seek
times is good, just slightly behind the best drives.

Audio '“
Digital Audio Extraction:

To test the digital audio
extraction performance of the Lite-On SHW-1635S, we again used Nero CD-DVD-Speed
to measure the transfer rate. The audio disc we used is slightly larger than the
disc used for the other tests, to be exact it's about 78 minutes long
(77:56:57).

 

The drive had no problems with
reading the audio disc at full speed; let us compare the result with other
drives:

The drive is extremely fast at
reading audio discs and the seek times are also very good, and the reported
quality seems good too, but let us try the advanced DAE quality test as
well.

Advanced
audio '“ DAE quality test:

Before we move on to testing DVD
read speeds, we will take a last audio test. This time we used the 'Advanced DAE
Quality Test" feature in CD-Speed.

 

This is one of the few times that
we can't put our finger on anything negative in this test! Everything appears to
be as good as it could possibly be.

DVD reading
performance:

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Again, we will use Nero CD-DVD
Speed to measure the reading performance, this time for various types of DVD
discs. The drive should read pressed single layer DVD-discs at 16X.

DVD '“
DVD-Video:

For our DVD reading performance
tests we are going to start with single and dual layered DVD video discs. While
only 1X speed is required to watch DVD movies, it's useful to be able to read
the discs at higher speeds if you're going to extract (rip) the content of the
disc to your hard drive.

 

 

This drive has no riplock and does
nearly reach 16x with the single layer disc. The double layer disc is
unfortunately only read at a low speed of 8x.

Let us take the good thing first;
the drive has no riplock for single layer media and is very fast with single
layer media. But for double layer discs it's limited to 8x reading speed, which
is pretty slow and we would like to see at least 12x reading speed.

 DVD+R/RW:

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For this test we used a Taiyo
Yuden 4X DVD+R and a Ricoh 4X DVD+RW with about 4,4Gb of data. Below are the
results:

Compared to the preview we could
see that DVD+RW reading speed are lowered to only 6x.

It's currently the fastest reader
for DVD+R media, but the DVD+RW reading speed is very poor - only 6x which is
slower than all other drives and even slower than the Lite-On SOHW-1673S!

DVD '“
DVD-R/RW:

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For this test we used a Taiyo
Yuden 4X DVD-R disc and a Verbatim 2X DVD-RW disc filled with about 4.4Gb of
data. Our test results are found below:

And the result is the same for
DVD-R and DVD-RW, speeds are lowered to 12x for DVD-R and 6x for DVD-RW.

It's currently the fastest reader
for DVD-R media as well, but the DVD-RW reading speed is also very poor - only
6x which is slower than all other drives and even slower than the Lite-On
SOHW-1673S!

Overall
thoughts:

It's a mix we may say, while CD
reading, audio reading and DVD+/-R reading is very good '“ the reading
performance for pressed double layer discs, CD-RW discs and DVD+/-RW discs is
lower than we would like to see.

But now it's time to head on to a
more interesting part: Writing CD-R and CD-RW
discs…

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The specifications of
the Lite-On SHW-1635S state that the drive is able to write CD-R discs at 48x
and CD-RW discs at 24x. Let us find out how the drive really performs in speed
and quality.

Writing Data
CD-R discs:

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Let us first take a look at the
CD-R write technology used by the Lite-On SHW-1635S:

 

As we could see, the Lite-On
SHW-1635S uses CAV (Constant Angular Velocity) to write at
its rated speed of 48x, this gives an average speed of 37.18x. Look below for
comparison with two other drives.

 

The BenQ DW1640 uses CAV
(Constant Angular Velocity) to write at its rated speed of
48x. This gives an average speed of 35.20x.

 

As we could see the Samsung
SH-W162C uses CAV (Constant Angular Velocity) writing
strategy to reach it rated speed of 48X. This gives an average speed of 37.01x.

And as a last test, we wrote a
disc containing 700Mb using Nero Burning ROM software. Writing method used is
DAO (Disc At Once), and the disc is set up as a non
multi-session disc with 'finalize disc" enabled.

 

Nero 7 is pretty stupid and closes
the overview window automatically, so this is the only image we have to show
from the writing process. By manually calculating the time used we could see
that it used 2 minutes and 39 seconds for writing the disc.

Excellent! Nothing more, nothing
less, it simply outperforms all the other drives, but is the writing quality
good? Let's find out!

Write
Quality:

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We will test CD-R discs from a
total of 9 different CD-R manufacturers. To really measure the write speed, we
used the 'create data CD" function in Nero CD-Speed. The discs were written at
the maximum speed that the drive supports. For the quality test, we used KProbe
2 which is a tool developed by a Lite-On employee. It runs under Windows and
works with drives made by Lite-On. Also note that different drives and different
reading speeds may affect the results obtained when scanning the discs. We used
a Lite-On LTR-52246S drive with firmware 6S0F and scanned the discs at 48X
speed.

A written CD-R disc will always
have some C1 errors; C1 errors are easily corrected by the drive's error
correction capabilities. The next level of errors is C2, while C2 errors could
also be corrected by most drive's error correction capabilities; they are not
wanted on a good quality disc. A good disc should not contain any C2 errors, and
preferably have an average C1 error amount of below 2.0 for the best discs, or
at least C1 average below 10.0 for good quality discs. After C2 errors there are
only un-correctable errors that will make a disc unusable.

Why wait any longer? Below are the
obtained results:

 

Brand:	Infiniti, thanks to Medea EU for providing it.
Manufacturer:	CMC Magnetics
Code:	97m26s66f
Disc Type:	CD-R
Recording Layer:	Dye Type 6: Short Strategy (Phthalocyanine)
Capacity:	79:59.71 (703MB)
Certified Speed:	52x
Write Speed:	48x
Write Time:	2m:34s
C1 Average/Sec:	1.41
C2 Average/Sec:	0.0

The CMC Magnetics discs seem to be
pretty good; they work very well with Lite-On SHW-1635S at least.

 

Brand:	MAM-E '“ thanks to MAM-E for providing it.
Manufacturer:	MAM-E (Mitsui)
Code:	97m27s58f
Disc Type:	CD-R
Recording Layer:	Dye Type 8: Short Strategy (Phthalocyanine)
Capacity:	79:59.74 (703MB)
Certified Speed:	52x
Write Speed:	16x
Write Time:	5m:23s
C1 Average/Sec:	2.04
C2 Average/Sec:	0.0

While the error level is good the
writing speed of 16x is not, Lite-On should really look into adding support for
this media at higher speeds.

 

Brand:	Verbatim Data Life Plus
Manufacturer:	Moser Baer India for Mitsubishi.
Code:	97m34s23f
Disc Type:	CD-R
Recording Layer:	Dye Type 3: Long Strategy (Cyanine or AZO)
Capacity:	79:59.73 (703MB)
Certified Speed:	52x
Write Speed:	48x
Write Time:	2m:34s
C1 Average/Sec:	0.36
C2 Average/Sec:	0.0

Excellent quality with
Mitsubishi/Verbatim media, highly recommended.

 

Brand:	Fujifilm
Manufacturer:	Ritek
Code:	97m15s17f
Disc Type:	CD-R
Recording Layer:	Dye Type 7: Short Strategy (Phthalocyanine)
Capacity:	79:59.70 (703MB)
Certified Speed:	52x
Write Speed:	48x
Write Time:	2m:36s
C1 Average/Sec:	0.41
C2 Average/Sec:	0.00

No problems with Ritek media
either, but notice that the quality of Ritek CD-R media may vary
greatly.

 

Brand:	Emgeton '“ thanks to Bell Technology for providing it.
Manufacturer:	Fornet International Pte. Ltd
Code:	97m26s07f
Disc Type:	CD-R
Recording Layer:	Dye Type 7: Short Strategy (Phthalocyanine)
Capacity:	79:59.71 (703MB)
Certified Speed:	56x
Write Speed:	40x
Write Time:	2m:56s
C1 Average/Sec:	1.46
C2 Average/Sec:	0.0

First 56x certified media we've
ever seen, but Lite-On SHW-1635S supports it at 40x only. The quality result is
good though.

 

Brand:	Miflop Extreme '“ Thanks to Miflop for providing it
Manufacturer:	Taiyo Yuden
Code:	97m24s01f
Disc Type:	CD-R
Recording Layer:	Dye Type 1: Long Strategy (Cyanine or AZO)
Capacity:	79:59.72 (703MB)
Certified Speed:	52x
Write Speed:	48x
Write Time:	2m:36s
C1 Average/Sec:	0.53
C2 Average/Sec:	0.00

And Taiyo Yuden gives excellent
results as it should.

 

Brand:	Infiniti '“ thanks to Medea EU for providing it.
Manufacturer:	SKC Co Ltd.
Code:	97m26s26f
Disc Type:	CD-R
Recording Layer:	Dye Type 6: Short Strategy (Phthalocyanine)
Capacity:	79:59.73 (703MB)
Certified Speed:	48x
Write Speed:	40x
Write Time:	2m:55s
C1 Average/Sec:	1.09
C2 Average/Sec:	0.00

The result is good with this media
too, but it's only supported at 40x writing speed.

 

Brand:	Miflop Lite '“ thanks to Miflop for providing it.
Manufacturer:	Digital Data Storage (using generic plasmon ID)
Code:	97m27s18f
Disc Type:	CD-R
Recording Layer:	Dye Type 8: Short Strategy (Phthalocyanine)
Capacity:	79:59.74 (703MB)
Certified Speed:	52x
Write Speed:	48x
Write Time:	2m:34s
C1 Average/Sec:	1.37
C2 Average/Sec:	0.00

Not the highest quality media, but
the result is still very good.

Brand:	BenQ, thanks to Daxon for providing it
Manufacturer:	Daxon (but with Hitachi Maxell ATIP)
Code:	97m25s29f
Disc Type:	CD-R
Recording Layer:	Dye Type 9: Short Strategy (Phthalocyanine)
Capacity:	79:59.74 (703MB)
Certified Speed:	52x
Write Speed:	48x
Write Time:	2m:35s
C1 Average/Sec:	2.11
C2 Average/Sec:	0.0

No problems with this media
either.

CD-ReWritable:

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The Lite-On SHW-1635S supports a CD-ReWriting speed of 24x; let us see how this compares to other writers.
Let us start with taking a look at the writing strategy it uses:

The Lite-On SHW-1635S uses Z-CLV, (Zone-Constant Linear
Velocity), to write at its rated speed of 24x, this gives an average speed of 22.57x. Let us see
how this compares to two competing drives.

 

The BenQ DW1640 uses P-CAV
(Partial-Constant Angular Velocity), to write at its rated speed of 32x, this gives an average
speed of 30.33x.

 

The NEC ND-3540A uses Z-CLV, (Zone-Constant Linear
Velocity), to write at its rated speed of 32x, this gives an average speed of
29.75x. 

Below, a comparison table with
results from other writers.

It's slower than most other drives
due to most other drives supporting 32x writing speed, we would like to see 32x
CD-ReWriting speed from Lite-On as well. But maybe the lower writing speed will
give better quality results? Read on to find out.

 

Brand:	Verbatim Data Life Plus
Manufacturer:	CMC Magnetics, but with Mitsubishi dye and ATIP
Code:	97m34s24f
Disc Type:	US CD-RW
Recording Layer:	Dye Type 4: Phase Change
Capacity:	79:59.74 (703MB)
Certified Speed:	24x
Write Speed:	24x
Write Time:	3m:58s
C1 Average/Sec:	70.07
C2 Average/Sec:	0.00

We have seen worse, but there is
still room for improvements.

Brand:	That's Write
Manufacturer:	Plasmon data systems
Code:	97m27s12f
Disc Type:	US CD-RW
Recording Layer:	Dye Type 2: Long Strategy (Phase Change)
Capacity:	74:41.00 (656MB)
Certified Speed:	24x
Write Speed:	24x
Write Time:	3m:49s
C1 Average/Sec:	173.20
C2 Average/Sec:	0.0

Luckily there are no
C2 errors, but the C1 error level is still pretty high.

Brand:	Emgeton '“ thanks to Bell Technology for providing this media.
Manufacturer:	Infodisc
Code:	97m25s31f
Disc Type:	US CD-RW
Recording Layer:	Dye Type 1: Phase Change
Capacity:	79:59.73 (703MB)
Certified Speed:	24x
Write Speed:	24x
Write Time:	4m:01s
C1 Average/Sec:	281.60
C2 Average/Sec:	0.49

The result with this media is not
good as there are several C2 errors near the end and the C1 error level is very
high too.

Summary:

The Lite-On SHW-1635S is
currently the fastest DVD-Writer we have tested when it comes to writing CD-R
media. And the writing quality is very good too! The media compatibility could
be improved though. For CD-RW it fails to impress as it only supports 24x
writing speed and the writing quality is not very good either.

But after all, it's a DVD-Writer,
so head on to next page and read about DVD-Writing performance and DVD media
compatibility…

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The specifications of this drive
tell us that it should write DVD+R discs at 16x and DVD-R discs at 16X speed. In
this part we will measure the write time for various types of DVD+/-R(W) discs.
We do also focus on write quality and media compatibility.

DVD-Writing
performance:

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We will start with taking a look
at the writing strategy used and compare it to other drives;

 

The Lite-On SHW-1635S uses CAV
(Constant Angular Velocity) to write at 16x speed. This
gives an average speed of 11.96x and a total writing time of 5m:59s. Let us also
take a look at writing a DVD-R disc:

As we could see it also uses CAV
(Constant Angular Velocity) to write DVD-R at 16x. This
gives an average speed of about 11.96x and a writing time of 5 minutes and 56
seconds. We have also included the results from two other drives
below.

 

The BenQ DW1640 uses CAV
(Constant Angular Velocity) to write at 16x. This gives an
average writing speed of 11.51x and the lowest time we have obtained is 5
minutes and 44 seconds. The drive uses a bit longer time than ideally since it
uses running OPC technology when writing (shown as small dips in the transfer
curve above).

 

The LG GSA-5163D uses P-CAV
(Partial-Constant Angular Velocity) to write at 16x.
The average speed for the LG GSA-5163D is 12.82x and total writing time is 5
minutes and 19 seconds. This is the fastest result we have got with all tested
writers so far, and is thus the record to beat for other drives.

Let us see how long of a time it
needs to create a disc with Nero. We used Nero Burning Rom to set up a new
UDF/ISO compilation containing 4483Mb of data, and started the write process. We
used the Disc-At-Once write method.

DVD+R

DVD-R

The DVD+R disc was finished in 6
minutes and 14 seconds, while the DVD-R disc was finished in 6 minutes and 22
seconds; again we are unable to show the usual picture due to the new Nero
version.

The Lite-On SHW-1635S is not the
fastest drive around, but it's still below the 6 minute mark in Nero CD-DVD
Speed. But let us take a look at the writing quality of this drive, maybe
Lite-On have finally gotten it right?

Write
quality:

---

You should first notice that this
is not a scientific and professional way to test the discs. But according to our
testing done in recent months, we would conclude that there is a clear link
between the quality reported when scanning the disc and the playability of the
disc in different devices. Also notice that different drives report different
amounts of errors. K-Probe was designed to work with Lite-On DVD-Writers. So we recommend using a
DVD-Writer from Lite-On, in this test we use a
Lite-On SOHW-1693S DVD-Writer, as already
said; remember that scans done with a Lite-On DVD-ROM or Lite-On combo drive can't be compared with the
results obtained with a Lite-On DVD-Writer.
Also remember that different PI/PO ECC sum
settings along with different reading speeds in K-Probe will affect the result,
we use these settings;  PI (Parity Inner) set to
summarize 8 ECC blocks, PIF (Parity Inner Failures)
set to summarize 1 ECC block, reading speed:
4X CLV (Constant Linear
Velocity). Setting the PI sum to 8 and the PIF sum to 1 will give a result that we may compare
to the standards for DVD+R/RW and DVD-R/RW.

But what is a good scan? That is a
discussion that we don't think will end soon, as different drives report
different amount of errors, some players is more picky about media than others,
and so on. But as a comparison we present you with a scan from two pressed DVD
discs:

This scan shows the results from a pressed DVD-ROM disc (Colin McRae Rally 2005).

 

This scan shows the result from a
pressed DVD-Video disk (Final Destination). Notice the error jump when shifting
to the second layer (the error level actually drops from the end of the first
layer to the beginning of the second layer).

If you read below you will see
that both the pressed DVD-discs are well within the standards.

Download the ECMA 267 Standard for DVD-ROM, the ECMA 337 Standard for DVD+R/RW and the ECMA 338 Standard for DVD-R/RW at http://www.ecma-international.org
if you want to look at the standards for yourself. Here is some data from the
ECMA standards (same for DVD-ROM, DVD-R/RW and DVD+R/RW):

Random
errors:

A row of an ECC Block that has at
least 1 byte in error constitutes a PI error. In any 8
consecutive ECC Blocks
the total number of PI errors before correction shall not exceed
280.

Here we see what a PI error is
defined as a row in an ECC block having 1 byte
or more containing errors. And that the sum of PI errors in 8 ECC blocks after each other should not exceed 280 PI
errors.

But what is a row and what is an
ECC block? Again we refer to the ECMA standards. We do not copy and paste everything
but if interested look in the ECMA standards.
A row is 182 bytes long where the last 10 bytes contain PI (Parity
Inner) information. An ECC block is 208
rows long where the last 16 rows contain the PO (Parity Outer)
information. This gives us a maximum possible PI error amount of 208 errors per
block and for 8 blocks after each other this sum is of course 8 times higher
giving a maximum possible amount of 1664 PIE-8 errors. In practical use a disc
with 1664 PIE-8 errors is unreadable.

According to our tests the
specified max PI-8 sum of 280 for good discs seems to be a good guideline, as
some readers have problems reading discs when the PI-8 errors is over 300 and
most players starts to have problems when the PI-8 error level reaches 600 or
more.

But what are the PIF errors that K-Probe reports? They are Parity
Inner Failures, meaning errors left after PI correction. Only the ECMA 337 standard describes the Parity Inner
Failures. So how is a Parity Inner Failure defined? Here are what ECMA 337 states:

'If a row of an ECC Block as
defined in 13.3 contains more than 5 erroneous bytes, the row is said to be
'PI-uncorrectable"."

In theory an ECC block may in the
worst case have 208 PIF since every ECC block is 208 rows long. But the ECMA 337
standard goes further and specifies the max amount of accepted PI Failures
(uncorrectable errors) allowed on a good disc:

'- In any ECC Block the number of PI-uncorrectable rows should not exceed
4."  

This means that when the PIF sum is set to 1 the maximum error value should
not exceed 4. The theoretical maximum value for PIF is 208 errors.

But what makes a disc unreadable?
A POF (Parity Outer
Failure) error will make the disc unreadable, but K-Probe does not
display the POF's.

Notice that there are other
aspects such as disc reflectivity, jitter, tracking errors and so on that also
will affect the readability of a DVD disc '“ but for this we do not have
measuring equipment available.

And another note is that we have
scanned the discs at 4X CLV speed, by lowering
the speed to 2X(DVD-R/RW)/2.4X(DVD+R/RW) or 1X the amount of reported errors may
drop on some discs. We scanned at 4X CLV due
to lower speeds taking to much time.

To see if there is a connection
between the reported amount of errors and readability of the discs we also
include the reading curve from a NEC ND-3540A DVD-Writer. A small speed
reduction near the end is still accepted on good discs, but serious reading
problems or reading failures is a bad sign.

Easier
explanation on how to read the test results.

---

Maybe this got too technical, and
you are wondering what to look for in KProbe
reports?

Use this as a guideline for good discs:

PI(Parity
Inner): No larger areas on the disc
should exceed 280 PI-8 errors, do not worry too much about high single spikes
that exceed 280.
PIF(Parity Inner
Failures): No larger areas on the disc should exceed 4 PIF-1
errors, do not worry too much about high single spikes that exceed 4.

And as always; lower is better
😉

And look at the reading curve;
does it look clean with no dips? Then it should be good, a small slowdown near
the end is acceptable.

DVD+R media
compatibility and write quality:

---

Brand:	BenQ '“ thanks to Daxon for providing it.
Manufacturer:	Daxon
Code:	DAXON.AZ3
Disc Type:	DVD+R
Capacity:	4483MB
Certified Speed:	16x
Write Speed:	16x
Write Time:	6m:08s
PI-8 errors Average/Sec:	6.44
PI-8 uncorrectable errors(PO) Avg/Sec:	0.05

No problems with this media, the
error levels are low and increases just slightly near the end. Recommended
media.

Brand:	Verbatim
Manufacturer:	Moser Baer India with Mitsubishi technology
Code:	MCC004
Disc Type:	DVD+R
Capacity:	4483MB
Certified Speed:	16x
Write Speed:	16x
Write Time:	5m:59s
PI-8 errors Average/Sec:	4.89
PI-8 uncorrectable errors(PO) Avg/Sec:	0.02

There are some more errors on the
last half of the disc, but not enough to cause any problems. Also recommended
media.

Brand:	ePro
Manufacturer:	Prodisc
Code:	Prodisc.R04
Disc Type:	DVD+R
Capacity:	4483MB
Certified Speed:	16x
Write Speed:	16x
Write Time:	5m:59s
PI-8 errors Average/Sec:	11.83
PI-8 uncorrectable errors(PO) Avg/Sec:	0.04

The error level increases
noticeably near the end, Lite-On should look into calibrating the drive better
for this media as it works with no problems in other drives. The reading curve
is still perfect and there will most likely not be problems

Brand:	RiDisc '“ thanks to e-net Distribution for providing this media
Manufacturer:	CMC Magnetics
Code:	CMC.MAG.M01
Disc Type:	DVD+R
Capacity:	4483MB
Certified Speed:	16x
Write Speed:	16x
Write Time:	6m:16s
PI-8 errors Average/Sec:	8.62
PI-8 uncorrectable errors(PO) Avg/Sec:	0.10

This media also works
satisfactorily and should not cause any problems.

Brand:	Acro Circle '“ thanks to Optodisc USA for providing this media.
Manufacturer:	Optodisc
Code:	Optodisc.R16
Disc Type:	DVD+R
Capacity:	4483MB
Certified Speed:	16x
Write Speed:	16x
Write Time:	6m:05s
PI-8 errors Average/Sec:	13.16
PI-8 uncorrectable errors(PO) Avg/Sec:	0.05

We could see that the error level
increases near the end, but not enough to cause any problems. Keep in mind that
this Optodisc media appears to be of better quality than most Optodisc media
available on the market.

Brand:	Traxdata '“ thanks to Conrexx for providing it.
Manufacturer:	Ritek
Code:	RITEK.P16
Disc Type:	DVD+R
Capacity:	4483MB
Certified Speed:	16x
Write Speed:	16x
Write Time:	6m:05s
PI-8 errors Average/Sec:	6.09
PI-8 uncorrectable errors(PO) Avg/Sec:	0.79

The first real failure, but we
suspect that it may be caused by poor media quality rather than a problem with
the Lite-On SHW-1635S drive. Avoid this media.

Brand:	That's Write
Manufacturer:	Philips/CMC Magnetics
Code:	Philips.C16 (Revision 001)
Disc Type:	DVD+R
Capacity:	4483MB
Certified Speed:	16x
Write Speed:	12x
Write Time:	7m:20s
PI-8 errors Average/Sec:	1.52
PI-8 uncorrectable errors(PO) Avg/Sec:	0.07

Unfortunately only supported at
12x, but the result is very good, and we could recommend this media if 12x
writing speed is enough for you.

Brand:	TDK
Manufacturer:	TDK / CMC Magnetics
Code:	TDK 003
Disc Type:	DVD+R
Capacity:	4483MB
Certified Speed:	16x
Write Speed:	16x
Write Time:	6m:21s
PI-8 errors Average/Sec:	21.44
PI-8 uncorrectable errors(PO) Avg/Sec:	0.10

Again the error level is a bit
high near the end, but still within the allowed limits. Lite-On probably needs
to optimise the drive better for this media.

Brand:	RiData '“ thanks to RiData for providing it.
Manufacturer:	Ritek
Code:	RITEK R03 (Revision 001)
Disc Type:	DVD+R
Capacity:	4483MB
Certified Speed:	8x
Write Speed:	8x
Write Time:	8m:29s
PI-8 errors Average/Sec:	6.93
PI-8 uncorrectable errors(PO) Avg/Sec:	0.03

No problems at all with this
media.

Brand:	Emgeton '“ thanks to Bell technology for providing this media
Manufacturer:	Infomedia
Code:	Infome.R20
Disc Type:	DVD+R
Capacity:	4483MB
Certified Speed:	8x
Write Speed:	8x
Write Time:	8m:36s
PI-8 errors Average/Sec:	2.75
PI-8 uncorrectable errors(PO) Avg/Sec:	0.07

No problems with this rather rare
media either.

Brand:	Datawrite titanium '“ thanks to e-net for providing it.
Manufacturer:	Prodisc
Code:	PRODISC.R03
Disc Type:	DVD+R
Capacity:	4483MB
Certified Speed:	8x
Write Speed:	8x
Write Time:	8m:31s
PI-8 errors Average/Sec:	1.51
PI-8 uncorrectable errors(PO) Avg/Sec:	0.26

The drive performed very well with
the Prodisc media and we have no problems recommending this media.

Brand:	Miflop extreme '“ thanks to Miflop media for providing it.
Manufacturer:	Taiyo Yuden
Code:	YUDEN000T02
Disc Type:	DVD+R
Capacity:	4483MB
Certified Speed:	8x
Write Speed:	8x
Write Time:	8m:27s
PI-8 errors Average/Sec:	0.91
PI-8 uncorrectable errors(PO) Avg/Sec:	0.01

And Taiyo Yuden works excellent as
expected. Highly recommended media.

 

Brand:	Acro Circle, thanks to Optodisc USA for providing it.
Manufacturer:	Optodisc
Code:	OPTODISC.OR8
Disc Type:	DVD+R
Capacity:	4483MB
Certified Speed:	8x
Write Speed:	8x
Write Time:	8m:38s
PI-8 errors Average/Sec:	1.84
PI-8 uncorrectable errors(PO) Avg/Sec:	0.13

No noticeable problems with this
media, but notice that the media we used for this review is among the better
Optodisc media on the market.

Brand:	Prodye Video
Manufacturer:	Unknown
Code:	Plasmon1C01
Disc Type:	DVD+R
Capacity:	4483MB
Certified Speed:	8x
Write Speed:	8x
Write Time:	9m:01s
PI-8 errors Average/Sec:	17.51
PI-8 uncorrectable errors(PO) Avg/Sec:	0.31

A bit high amount of errors at the
start of the disc, but overall an acceptable result with this rather low quality
media.

Brand:	ProDVD
Manufacturer:	UME Disc '“ Hong Kong.
Code:	AML 002
Disc Type:	DVD+R
Capacity:	4483MB
Certified Speed:	8x
Write Speed:	8x
Write Time:	8m:47s
PI-8 errors Average/Sec:	2.27
PI-8 uncorrectable errors(PO) Avg/Sec:	0.04

A surprisingly good result with
this low quality media.

Brand:	Commodore
Manufacturer:	Vanguard Disc Inc.
Code:	VDSPMSAB002
Disc Type:	DVD+R
Capacity:	4483MB
Certified Speed:	8x
Write Speed:	8x
Write Time:	9m:57s
PI-8 errors Average/Sec:	4.55
PI-8 uncorrectable errors(PO) Avg/Sec:	0.02

Another surprise, this low quality
media also gave pretty good results.

Head on to next page and read
about DVD-R compatibility and write quality as well as DVD+/-RW writing quality
and speed...

---

DVD-R media
compatibility and write quality:

---

Brand:	BenQ '“ thanks to Daxon for providing it.
Manufacturer:	Daxon
Code:	DAXON016S
Disc Type:	DVD-R
Capacity:	4489MB
Certified Speed:	16x
Write Speed:	16x
Write Time:	5m:56s
PI-8 errors Average/Sec:	32.99
PI-8 uncorrectable errors(PO) Avg/Sec:	0.10

There is a noticeable amount of PI
errors at the last half of the disc, so it looks like Lite-On needs to work on
the writing strategy for this media. The disc does still comply to the
specifications and did read back at full speed with no problems.

Brand:	Traxdata '“ thanks to Conrexx for providing this media
Manufacturer:	Ritek
Code:	RitekF1
Disc Type:	DVD-R
Capacity:	4489MB
Certified Speed:	16x
Write Speed:	16x
Write Time:	6m:11s
PI-8 errors Average/Sec:	46.05
PI-8 uncorrectable errors(PO) Avg/Sec:	0.10

Again, it looks like Lite-On needs
to work on optimizing the writing strategy, the error levels exceeds the allowed
limit and we could not recommend this media.

Brand:	Verbatim Data Life Plus
Manufacturer:	CMC Magnetics using Mitsubishi technology
Code:	MCC03RG20
Disc Type:	DVD-R
Capacity:	4489MB
Certified Speed:	16x
Write Speed:	16x
Write Time:	5m:56s
PI-8 errors Average/Sec:	6.92
PI-8 uncorrectable errors(PO) Avg/Sec:	0.02

A bit more errors towards the end,
but not enough to cause any problems. Recommended media.

Brand:	Miflop Extreme '“ thanks to Miflop media for providing it.
Manufacturer:	Taiyo Yuden
Code:	TYG03
Disc Type:	DVD-R
Capacity:	4489MB
Certified Speed:	16x
Write Speed:	16x
Write Time:	6m:10s
PI-8 errors Average/Sec:	4.25
PI-8 uncorrectable errors(PO) Avg/Sec:	0.01

A very good result with this
media, highly recommended.

Brand:	Unbranded silver media distributed by e-net distribution.
Manufacturer:	CMC Magnetics / TDK
Code:	TTH02
Disc Type:	DVD-R
Capacity:	4489MB
Certified Speed:	16x
Write Speed:	16x
Write Time:	5m:57s
PI-8 errors Average/Sec:	2.38
PI-8 uncorrectable errors(PO) Avg/Sec:	0.01

A surprisingly good result with
this media, we have no complaints at all!

Brand:	ePro
Manufacturer:	Prodisc
Code:	Prodisc.F02
Disc Type:	DVD-R
Capacity:	4489MB
Certified Speed:	16x
Write Speed:	16x
Write Time:	5m:56s
PI-8 errors Average/Sec:	2.85
PI-8 uncorrectable errors(PO) Avg/Sec:	0.07

Another very good result and we
have no problems recommending this media.

Brand:	Acro Circle '“ thanks to Optodisc USA for providing this media.
Manufacturer:	Optodisc
Code:	OptodiscR016
Disc Type:	DVD-R
Capacity:	4489MB
Certified Speed:	16x
Write Speed:	16x
Write Time:	6m:07s
PI-8 errors Average/Sec:	3.72
PI-8 uncorrectable errors(PO) Avg/Sec:	0.02

Another surprisingly good result,
but keep in mind that this Optodisc media appears to be of better quality than
most Optodisc media available on the market.

Brand:	Emgeton '“ thanks to Bell technology for providing this media
Manufacturer:	Infomedia
Code:	Infomedia.R20
Disc Type:	DVD-R
Capacity:	4489MB
Certified Speed:	8x
Write Speed:	8x
Write Time:	8m:37s
PI-8 errors Average/Sec:	5.65
PI-8 uncorrectable errors(PO) Avg/Sec:	0.03

This pretty rare media works very
well with this drive.

Brand:	RiData '“ thanks to Advanced media USA for sending this media
Manufacturer:	Ritek
Code:	RITEKG05
Disc Type:	DVD-R
Capacity:	4489MB
Certified Speed:	8x
Write Speed:	8x
Write Time:	8m:47s
PI-8 errors Average/Sec:	0.02
PI-8 uncorrectable errors(PO) Avg/Sec:	1.00

The overall PIF error level is too
high for our liking; we did try two discs with the same result so it looks like
Lite-On should look into improving the writing strategy for this media. The
reading curve is still perfect though.

Brand:	MiFlop Extreme '“ thanks to MiFlop for providing it.
Manufacturer:	Taiyo Yuden
Code:	TYG02
Disc Type:	DVD-R
Capacity:	4489MB
Certified Speed:	8x
Write Speed:	8x
Write Time:	8m:41s
PI-8 errors Average/Sec:	3.94
PI-8 uncorrectable errors(PO) Avg/Sec:	0.01

Excellent '“ as expected with Taiyo
Yuden. Highly recommended media.

Brand:	Datawrite silver printable '“ thanks to E-net distribution for providing this media.
Manufacturer:	Prodisc
Code:	ProdiscF01
Disc Type:	DVD-R
Capacity:	4489MB
Certified Speed:	8x
Write Speed:	8x
Write Time:	8m:45s
PI-8 errors Average/Sec:	7.00
PI-8 uncorrectable errors(PO) Avg/Sec:	0.17

A bit too many PIF spikes near the
end to be called perfect, but there is no problems with reading back the disc.
In practical use there will most likely not be any issues. 

Brand:	Acro Circle '“ thanks to Optodisc USA for providing it.
Manufacturer:	Optodisc
Code:	OPTODISCR008
Disc Type:	DVD-R
Capacity:	4489MB
Certified Speed:	8x
Write Speed:	8x
Write Time:	9m:01s
PI-8 errors Average/Sec:	11.31
PI-8 uncorrectable errors(PO) Avg/Sec:	0.07

Another acceptable result and the
disc is fully readable with no slowdowns. Notice that this Optodisc media is
probably of higher quality than the average Optodisc media on the
market.

Brand:	Datawrite Titanium '“ thanks to E-net distribution for providing this media
Manufacturer:	CMC Magnetics/TDK
Code:	TTG02
Disc Type:	DVD-R
Capacity:	4489MB
Certified Speed:	8x
Write Speed:	8x
Write Time:	8m:21s
PI-8 errors Average/Sec:	1.70
PI-8 uncorrectable errors(PO) Avg/Sec:	0.01

It can't get much better than
this, highly recommended media!

Brand:	Princo
Manufacturer:	Princo
Code:	PRINCO8X02
Disc Type:	DVD-R
Capacity:	4489MB
Certified Speed:	8x
Write Speed:	8x
Write Time:	8m:41s
PI-8 errors Average/Sec:	58.34
PI-8 uncorrectable errors(PO) Avg/Sec:	0.16

With Princo you know what you get
at least; some real garbage media. Don't buy Princo, not even if they throw it
after you '“ as you will most likely end up with unreadable discs, which is not
worth it regardless of media price.

Brand:	Tuffdisc '“ thanks to E-Net distribution for providing this media.
Manufacturer:	CMC Magnetics
Code:	CMC.MAG.AE1
Disc Type:	DVD-R
Capacity:	4489MB
Certified Speed:	8x
Write Speed:	8x
Write Time:	8m:25s
PI-8 errors Average/Sec:	3.73
PI-8 uncorrectable errors (PO) Avg/Sec:	0.03

No problems with this media
either.

Overall
thoughts: With 8x media the Lite-On
SHW-1635S is very good and even less known media works very well. It do also
work well with many 16x media types, but there is still some work to do before
it could match the writing quality of manufacturers like BenQ and NEC at 16x.
But having that said we could see a clear improvement from previous Lite-On
drives, which is a very good sign, and as usual with Lite-On drives the media
compatibility is very good '“ only one disc was not written at certified speed.

Re-Writing
data:

---

The Lite-On SHW-1635S supports
rewriting DVD-RW at 6x and DVD+RW at 8x speed; let us write two discs in Nero
CD/DVD speed and Nero Burning ROM to see how fast it is.

Here is the writing result for
writing the 6x DVD-RW disc:

Lite-On SHW-1635S uses Z-CLV
writing technology to write the DVD-RW disc at 6x. Total recording time is
around 10 minutes and 30 seconds.

And here is the result with 8x
DVD+RW writing:

Lite-On SHW-1635S uses Z-CLV
writing technology to write the DVD+RW disc at 8x. Total recording time is about
7 minutes and 30 seconds.

Writing Quality
with DVD Re-Writable discs:

---

Due to requests from our readers
we will add a few write quality tests with ReWritable media. Settings and
testing procedures are the same as used earlier in this review so you may want
to go back and read them if unsure.

DVD+ReWritable
media:

Brand:	Unbranded '“ thanks to BenQ for providing this media.
Manufacturer:	Ritek using Ricoh technology.
Code:	RICOHJPNW21
Disc Type:	DVD+RW
Capacity:	4483MB
Certified Speed:	8x
Write Speed:	8x
Write Time:	7m:27s
PI-8 errors Average/Sec:	462.30
PI-8 uncorrectable errors(PO) Avg/Sec:	4.37

Well, to be honest, the writing
quality is very bad. The PIF level is still not high enough to make the disc
unreadable though. But overall very disappointing and Lite-On should look into
this issue. It may be worth mentioning that this disc is used in other reviews
before this review, we full erased the disc before we wrote to it.

Brand:	Traxdata
Manufacturer:	Ritek
Code:	RITEK008
Disc Type:	DVD+RW
Capacity:	4483MB
Certified Speed:	8x
Write Speed:	8x
Write Time:	7m:31s
PI-8 errors Average/Sec:	567.50
PI-8 uncorrectable errors(PO) Avg/Sec:	193.20

The quality of the written disc is
so bad that the Lite-On SOHW-1693S freaked totally out when scanning the disc!
And sure enough '“ the disc is unreadable. This disc is not previously used in
other reviews.

Brand:	Unbranded MKM '“ thanks to LG Korea for providing this media.
Manufacturer:	Mitsubishi Kagaku Media
Code:	MKM.A03
Disc Type:	DVD+RW
Capacity:	4483MB
Certified Speed:	8x
Write Speed:	8x
Write Time:	7m:31s
PI-8 errors Average/Sec:	345.20
PI-8 uncorrectable errors(PO) Avg/Sec:	4.22

Another very poor result and
Lite-On should really look into improving the writing quality for this media.
This disc is previously used in other reviews and full erased for this
review.

DVD-ReWritable
media:

---

Brand:	Mitsubishi '“ thanks to Verbatim UK for providing this media.
Manufacturer:	Mitsubishi
Code:	MCC01RW6X01
Disc Type:	DVD-RW
Capacity:	4489MB
Certified Speed:	6x
Write Speed:	6x
Write Time:	10m:31s
PI-8 errors Average/Sec:	85.32
PI-8 uncorrectable errors(PO) Avg/Sec:	12.13

Again the Lite-On SHW-1635S gave
back a very poor result. The disc is not used in other reviews.

Brand:	Traxdata '“ thanks to Conrexx for providing this media.
Manufacturer:	Ritek
Code:	RITEKW06
Disc Type:	DVD-RW
Capacity:	4489MB
Certified Speed:	6x
Write Speed:	6x
Write Time:	10m:35s
PI-8 errors Average/Sec:	28.56
PI-8 uncorrectable errors(PO) Avg/Sec:	0.19

The best RW result we got, but
it's still not very good. We have seen better results with several other
writers, so Lite-On have some work to do. This disc is not used in other
reviews.

To sum it
up:
The DVD+/-RW writing quality is horrible, Lite-On clearly have some work to do
here. We tested several discs as well as scanning the discs in several drives
and the results was always the same '“ very poor.

But let us now look at another
aspect of this drive; double layer DVD+R and dual layer DVD-R
writing…

---

DVD+R Double
Layer writing speed and compatibility:

---

The Lite-On SHW-1635S supports 8x
DVD+R DL writing, let us see how good it really is.

Testing
procedure: We used Nero CD-DVD Speed to
create a test disc, this way we could also see the writing strategy the drive
uses.

Lite-On SHW-1635S doesn't support
any current double layer media at 8x and we were thus not able to test the
writing speed and quality at 8x. You could read the preview for a result when
using a hacked firmware to write Verbatim 2.4x DVD+R DL at 8x. Verbatim 2.4x
DVD+R DL is officially supported at 4x and written using CLV technology, this
gives a writing time of about 27 minutes for a full disc. We would like to see
this media supported at 8x like most other drives capable of 8x DVD+R DL
do.

Brand:	Verbatim '“ thanks to Verbatim UK for providing this media.
Manufacturer:	Mitsubishi (Singapore)
Code:	MKM 001
Disc Type:	DVD+R DL
Capacity:	8152MB
Certified Speed:	2.4x
Write Speed:	4x
Write Time:	26m:58s
PI-8 errors Average/Sec:	0.77
PI-8 uncorrectable errors(PO) Avg/Sec:	0.04

The result is very good, but that
was expected, as the writing speed is only 4x. We would like to see 8x writing
speed with this media.

Brand:	Traxdata '“ thanks to Traxdata for providing it.
Manufacturer:	Ritek
Code:	Ritek.D01
Disc Type:	DVD+R DL
Capacity:	8152MB
Certified Speed:	2.4x
Write Speed:	2.4x
Write Time:	44m:09s
PI-8 errors Average/Sec:	8.43
PI-8 uncorrectable errors(PO) Avg/Sec:	0.31

A surprisingly good result with
this rather problematic media. Looks like the Lite-On is really fully calibrated
for this media.

Brand:	eProformance
Manufacturer:	Prodisc
Code:	PRODISC.D01
Disc Type:	DVD+R DL
Capacity:	8152MB
Certified Speed:	2.4x
Write Speed:	2.4x
Write Time:	43m:44s
PI-8 errors Average/Sec:	72.69
PI-8 uncorrectable errors(PO) Avg/Sec:	0.60

Another variable media type and
the error level on the second layer is higher than we would like to
see.

Brand:	That's Write '“ thanks to That's Write for providing it.
Manufacturer:	CMC Magnetics
Code:	Philips.CD2
Disc Type:	DVD+R DL
Capacity:	8152MB
Certified Speed:	2.4x
Write Speed:	4x
Write Time:	27m:03s
PI-8 errors Average/Sec:	8.20
PI-8 uncorrectable errors(PO) Avg/Sec:	0.03

A very good result, also consider
that the disc wrote at 4x. The sample disc we used was heavily scratched too as
the media got heavily damaged during shipping, since the result is still
acceptably good we choose to include the result anyway '“ the reading issues
around the layer change is likely to be caused by the scratches as they are
clearly visible on the outer edge of the disc.

Here are some comparison results
against other drives:

*Default book type
of the drive is DVD+R DL, the book type must be manually changed to DVD-ROM
using for example Lite-On's own booktype setting tool. This is a negative point
in our opinion as many users/buyers will not know what booktype and bitsetting
is. Setting the booktype to DVD-ROM is essential for the disc to play on many
standalone players.

Summary: Lite-On SHW-1635S gives
very good writing quality with most DVD+R DL media types. But we would like to
see MKM001 DVD+R DL media supported at 8x as well as automatic DVD-ROM
bitsetting as a default setting.

DVD-R Dual Layer
writing speed and compatibility:

---

The Lite-On SHW-1635S supports 4x
DVD-R dual layer writing speed; let us take a look at writing speed and writing
quality.

Testing
procedure: We used Nero CD-DVD Speed to
create a test disc, this way we could also see the writing strategy the drive
uses.

Lite-On SHW-1635S uses CLV to
write the DVD-R DL disc at 4x. This gives a total recording time of 27 minutes
and 34 seconds '“ as expected with 4x writing speed. We would still like to see
6x writing speed like Pioneer and NEC offers.

Brand:	Verbatim '“ Thanks to Verbatim UK for providing it.
Manufacturer:	Mitsubishi (Singapore)
Code:	MKM01RD30
Disc Type:	DVD-R DL
Capacity:	8148MB
Certified Speed:	4x
Write Speed:	4x
Write Time:	27m:34s
PI-8 errors Average/Sec:	7.60
PI-8 uncorrectable errors(PO) Avg/Sec:	0.02

Very good, although not the best
we have seen with this media.

Summary: Verbatim DVD-R DL works
well with this drive, but we would like to see 6x/8x DVD-R DL speed like
NEC/Pioneer offers with their latest drives.

Before we complete this review,
let us run the drive through some advanced tests at next
page…

---

 The 'Sheep
test":

For this test, we will use the
Sheep tests made by Alexander Noé. Why is it called
Sheep Test? That is because the symbol of the first 1 to 1 copy program called
CloneCD is a sheep. When looking at supported writers, you will notice that the
feature list has sheep to indicate if a feature is supported or not. In this
case we are interested in the writer's ability to backup/write weak sectors.
Also called: 'Correct EFM encoding of regular bit-patterns".

⋅
No sheep:
Can't backup any Safedisc 2 versions without the help of software
tricks
⋅
1 Sheep:
Can backup Safedisc 2 up to version 2.4x without software tricks

⋅
2 Sheep:
Can backup Safedisc 2, including version 2.5x
⋅
3 Sheep:
Can write all possible weak sectors, few if any writers could do this.

One of our forum moderators,
Womble, has written a guide concerning
the 'Sheep Test" that could be found here.

In the screenshot below we see
that the Lite-On SHW-1635S supports all available write and read features in
CloneCD:

The Lite-On SHW-1635S supports
DAO-RAW96 recording mode. This means that it can write uncorrected data and
subchannel data.

Below are our results from the
'Sheep Tests":

The Lite-On SHW-1635S qualifies as
a two sheep writer and could also backup Safedisc version up to 2.90 or maybe
even higher.

Overburning:

---

To test the CD overburning
capabilities of the Lite-On SHW-1635S we used the overburning test in Nero
CD-DVD-Speed. According to Nero CD-DVD speed the drive can overburn to more than
99 minutes.

 

Media used is Ritek 99-minute
media. We had problems with Nero and thus used the create data disc function in
Nero CD-DVD Speed with overburning enabled and set to 99:57.74

 

Nero CD-DVD speed wrote the disc
with no problems up to almost 100 minutes

 

There are no problems with reading
the 99-minute disc.

Now, this is the end of the
testing part of this review, head over to the summary and conclusion at the next
page…

 Positive:

---

• Overall good
  specifications.
• Very good DVD-media
  support as almost every disc is supported at certified speed.
• Very good CD-Writing
  quality.
• Very good DVD+R DL and
  DVD-R DL writing quality.
• Very good retail
  package that includes extra black front bezel.
• Excellent audio
  extraction capabilities.
• Fast
  CD-Reader.
• Reads DVD+/-R at
  16x.
• No riplock for reading
  DVD-Video discs.
• Supports bitsetting
  for DVD+R/RW/R DL, but needs to be enabled.
• Good error testing
  capabilities.
• Good community support
  and many 3^rd party programs that works with the drive.
• Supports
  reading/writing 99 minute CD-R media.
• Good drive for backing
  up protected PC games.

Negative:

---

• CD-R media
  compatibility could be further improved.
• Awful DVD+/-RW writing
  quality.
• Only 24x CD-RW writing
  speed, and writing quality needs to be improved too.
• Only 32x CD-RW reading
  speed.
• Very low DVD+/-RW
  reading speed of only 6x.
• Only 8x reading of all
  double layer media types.
• DVD-writing quality
  with certain 16x media could be improved.
• Doesn't support 6x/8x
  DVD-R DL.
• Doesn't support any
  current DVD+R DL discs at 8x speed.
• Doesn't set DVD+R/RW/R
  DL media to DVD-ROM booktype as default.
• Doesn't support
  'overspeeding" media (Writing media at higher speeds than what it is certified
  for).

Conclusion:

---

  Have Lite-On been able to fix the issues we pointed out in our
SOHW-1673S review? Well, some of them, but they did also introduce some new
issues. Let's summarize the main positive and negative points below.

The main
positive points: The Lite-On SHW-1635S
is a very good CD-Writer. They have also greatly improved the DVD-Writing
quality and at 8x the quality are very good. The Lite-On SHW-1635S is also a
fast CD-Reader and excellent Audio CD-Reader and also reads DVD+/-R at 16x. And
you also get a good program bundle and an extra front bezel in the retail
package. And not to forget that this drive also supports bitsetting, error
scanning of written discs and has a huge community support with lots of
3^rd party programs designed just for Lite-On drives. Interested? Then
our Lite-On forum is a great place to start reading!

The main
negative points: While they improved in
some areas they did also break some things. The DVD+RW and DVD-RW writing
quality of this drive is just horrible, so don't buy this drive if you plan on
using such media. The CD-RW speed is only 24x and the quality could be better
too. The reading speed for several media types is lower than we would like to
see as well, especially DVD+/-RW reading speed is low with only 6x '“ this is
even slower than previous Lite-On drives. The strange thing is that the reading
speeds were higher with earlier firmware versions. And we can't get around it,
the 16x DVD-Writing quality is still not as good as the competition for some
media types '“ but it's better than previous Lite-On drives. And the drive is
also selling as an 8x DVD+R DL capable drive, but doesn't support any current
DVD+R DL media at 8x '“ we would like to see 8x support for Verbatim 2.4x DVD+R
DL.

To sum it all up, this is the best
we could say: 'This drive will work pretty
well if you don't care about writing DVD+/-RW media, and could live with low
reading speeds of some media types" We
hope that Lite-On will soon be able to make a drive that works acceptably in
every area, and not just some areas.

You
may discuss/comment this review below or in this
forum thread. This forum thread may also be used to ask questions around
this drive or request additional tests.

Thanks
to:

 Conrexx for providing the Traxdata media used in
this review. Conrexx technology is the
supplier of Traxdata media as well as other Ritek media brands for whole Europe, Africa and Middle
East.

 For providing some of the That's Write media used in this review. That's
Write focus on providing quality media at reduced prices in
Europe.

 For providing some of the Memorex media used in this
review. Memorex is one of the largest providers
of all types of media for larger parts of the world.

 For providing us with Miflop Extreme and Lite media. Miflop media aims at providing
both chea and expensive (Taiyo Yuden) quality media.

For providing the RiData media used in this
review. RiData is a Ritek brand and thus you are sure to get Ritek manufactured discs when buying RiData media.

For providing the Daxon and BenQ media used in this review. Daxon manufacture high quality media
for many large OEM customers lke BenQ and Sony.

 For providing the Verbatim DVD+R9 double layer media used in this
review. Verbatim provides high quality media
almost over the whole world.

 For providing the Infiniti media used in this review. Medea is a long time player in the
optical disc market.

 E-Net Distribution '“ United
Kingdom for providing the DVD+R 8x and DVD-R 8x media used in this review. E-Net Distribution is currently
Europe's largest supplier of CD and DVD media.

Bell Technology spol
s.r.o. '“ Czech Republic for providing some of the media used in this
review.

 Optodisc USA for sending the Acro Circle media used in this
review.

Looking for CD and
DVD-Media in Norway? Visit www.norwaydisc.no the Norwegian
specialist on CD and DVD Media!