What kind of power is needed for SLi?

[ChrisA]

Im thinking of building a new system and it will probably end up SLi as i have a single 9600GT at present. Just wondering what kind of Wattage PSU to go for. I dont think the 9600GTs are particularly power hungry.

system will be:
E8400
750i Sli Board
2x 9600GTs
4Gb (2 x 2Gb)PC2-6400-800
2xSATA HDDs

I may want to play about with OC'ing one day too.

I was thinking 525-625W maybe, can anyone help?

 

[geofelt]

A quality psu from Corsair, Antec, Seasonic, or PC P&C that has two pci-e connectors will do the job.
Currently there is a good deal on the PC P&C silencer610 for $70 after rebate:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817703005

 

[ChrisA]

Thanks Geofelt
i was thinking of getting a Enermax modu82+, my PSU is by far the loudest part of my PC and they are meant to be very efficient and almost silent.

http://www.silentpcreview.com/article699-page1.html

What i really need to know is what kind of Wattage i should be looking at?

 

[geofelt]

What i really need to know is what kind of Wattage i should be looking at?

That's the problem. Wattage is not as important as the amps that can be delivered on the 12v rails.

I think Enermax is a quality unit with enough amps(50), so you should be OK there.

If you want quiet, get a sufficiently strong unit that will operate in the middle 2/3 of it's power range. That will keep the fan from spinning up and becoming noisy. The 625w unit referenced would be good.

 

[huron]

Well stated geofelt. There are PSU calculators out there, but the 12v rail is the most important for GPU dependent items like SLI.

Don't take this for gospel, but it gives you an idea:

http://extreme.outervision.com/psucalculator.jsp

 

[ChrisA]

that test came out at 316w fyi. sounds like the 625 would be better suited... 'gulp' they are £95, 525w is only £61.