what is the recommended wattage on a 8800 gtx sli?
Nvidia suggest a power consumption of 140-170W depending on the manufacturer and the cooling device since it can also drain some power. Real tests made by the guys at Anandtech revealed that a high end PC that uses an 8800GTX series card consumes about 320W. And I�m talking about a high priced Core 2 Duo with 2GBs of Ram here.
The conclusion is simple. 25-27A on the +12V lines for a single 8800 is more than enough. And in case you need a SLI configuration, make sure you have at least a 30-34A capable PSU. Note that not all PSUs run according to their specification and current on the +12V line may be lower in reality. In order to stay away from trouble, a good quality 430W-480W from a top manufacturer should be enough.
I used to run two XFX GTX-8800GTX's in SLI and my 550watt, 650watt peak power supply was adequate for the two video cards, one sound card, three hard drives, one dvd and one cd drive. And I over clocked my duo core from 2.4 ghz to 3.4 ghz and still had power to boot.
Check this Power Supply Calculator out. Its very accurate and it works. If you need any help with it, let me know.
http://www.extreme.outervision.com/psucalculatorlite.jsp
I'm now running two EVGA GTX-580's in SLI and over clocked to 950mhz and I'm using an Antec 1200 watt PSU. I personally would recommend that you purchase at least a 1000 watt PSU for your two video cards and for future SLI video card upgrades. The GTX-560 cards have dropped in price dramatically and are great cards.
Even two AMD 5850's in crossfire are great and more affordable now.
I hope this helps you out.
Peace and happy gaming.
