One of the loudest complaints to come from the fickle gaming crowd has always been the noise level of the Xbox 360. Call us spoiled, but these things are important. Fortunately for our sensitive gaming ears, Microsoft has finally begun upgrading the standard DVD drive in the 360, leading to a "super-quiet" console that (according to owners of said upgrade) further improves your gaming experience by loading "stuff a bit faster and smoother."
No word on how potential Xbox 360 owners or those looking to upgrade can determine
before purchase whether they'll come home with a quieter machine. However, the Xbox Scene members indicate that consoles manufactured on or after November 06 were the first to feature the quiter BenQ model.
As soon as that HDMI version with the 65nm process CPU hit shelves, I'm
totally jumping in
Source