Going by various reports, Microsoft has upgraded its new Xbox360 consoles' optical drives with a quieter DVD drive. For those interested, it is a BenQ VAD6038 going by this CVG article. As the consoles with the new drive reached the stores towards the end of the year, some recent buyers may be lucky enough to have one of these quieter consoles.
Besides running quieter, the drive also solves some (but not all) of the playback issues, such as with Oblivion and improves loading times of games, especially between scenes where the player needs to read from the disc. On the other hand, this is not the first time Microsoft has changed the drive used in its Xbox 360 console.
