The Steam Box seems highly unlikely to include an optical drive, as the whole point of Steam is online distribution.Strazdas said:if anything consoles were always way more noisier becuase the dvd/BR drive is the noisiest part of computer anyway, and with PC your running off installed thing and not the disc.
Also, fans. Some computers have much noisier fans than their optical drives. The Steam Box may not even have any fans. And the size is most likely to be much smaller than a conventional PC.