may i also suggest the Antec True Power series. they're some of the best PSU's on the market and very quiet, too. they are temperature sensing so if things get too hot, they'll speed up the fans to protect your equipment. also, you can plug your case fans into a special power connector on it so that it will control their speed, as well. my computer is a monster heat producer but runs nearly silent, and a lot of the remaining noise is from the hard drives whining. interior sound insulation is a great thing, too. i have a 550 watt version and a 400-something watt version, and they're both great.