How much wattage is needed for an SLI setup?

[ajrunke]

Ok, my main question is in the title, but here's a little more info. I currently have a 450w powersupply and a single 8800gt. Anyway, I am going for an sli setup, but how do I figure out how much wattage is needed for that setup? My card requires 400w. I sort of forgot some things that I read about how sli works...I'm pretty sure you don't need to double your power requirements because the cards are not working in unison...one is rendering and the other is providing another task...probably way off base (and sounded stupid), but they're both not ever going to be requiring 800w total.........???

I do know I need to pay attention the the 12v rail ratings as they're not all the same....

 

[dassox]

The 400W number doesn't get multiplied for each additional card you add, the 400W for a single card also takes into account the rest of the system components. You tend to want to add about 100-150 Watts over the recommendation for 1 card, though personally I'd go with something at or above 550-600W.

http://www.anandtech.com/video/showdoc.aspx?i=3140&p=13

^has the 8800gt pulling 209 watts under load, while the 8800gt in SLI it has at 327 watts.

Hope that helped

 

[Mousemonkey]

I'm using a Corsair 620HX myself and I've seen 8800GT Sli rigs refuse to enable Sli mode with a no name 600w PSU, so get a good one.

 

[ajrunke]

The 400W number doesn't get multiplied for each additional card you add, the 400W for a single card also takes into account the rest of the system components. You tend to want to add about 100-150 Watts over the recommendation for 1 card, though personally I'd go with something at or above 550-600W.

http://www.anandtech.com/video/showdoc.aspx?i=3140&p=13

^has the 8800gt pulling 209 watts under load, while the 8800gt in SLI it has at 327 watts.

Hope that helped

That's what I needed. Thanks for the link too, I appreciate it.