Re: Corsair 520 Psu! unless you are running 8800gtx's in sli i think you will be fine. 2 8800gts' in sli with a quad core 2 hdd's 2 optical drives with a few case fans is still not too much for the psu. I am using the corsair hx520 right now and its great.
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Laptop:
MacBook 2.2GHz Santa Rosa | 120GB HDD | 4GB ram
Desktop:
Intel C2D E6300 @ 3.2GHz | 4GB ram | 880GB total HDD space | Gigabyte P965-DS3 | eVGA 8800GTS 640mb | Corsair HX 520 | Audigy 2 ZS platnium | Antec 900 |