Computer Power Supply + SLI Video Cards

Good day everyone,

I finally upgraded my pc yesterday, got my motherboard, cpu , ram and video cards in. One problem. It only has 2 6 pin connectors. Each card takes 2 6 pins. I can purchase 2 additional adapters that take from 2 4 pin(12 v I think) connectors to make 1 additional 6 pin.

So I would be using 4x 4pin connectors to create the other 2x 6 pins I need. My psu is 850 watts, with 2 12v rails rated at 30 amps each. I called my local frys electronics store and they told me I need a better power supply, stating that my 2 gtx 260's take 40 amps each, which on nvidia's site, it says 36.

Am I at risk for blowing my power supply? I am only running 1 hd, 1 dvd drive and am not overclocking my cpu.

I don't want to shell out for another psu if I dont have to. My dad has a similar setup, but runs a 900 watt psu (unsure of the amperage) , and he says it should be fine.

Thoughts and input is appreciated!! (of course)

 

Off the top of my head I'd say you should be fine with the 850W PSU but the need to convert additional connectors is slightly concerning.

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

Plunk the bits of your rig in there and it will tell you how big a PSU you need.

 

You SHOULD be okay, My advice, as soon as you can buy an SLI compatible power supply that is 1000w or better.

 

Lol this site says 475 watts.

Im gonna bite the bullet and just try.

I fried my old psu when i was using a 500watt when I got the 1st card, that for sure isnt enough when your are overclocking the crap out of it!

 

I don't think you'll draw enough to damage anything. If the PSU is not up to snuff you'll probably experience some stability issues when you start putting the graphics cards under stress (gaming etc.).

 

Is the PSU 80+ certified? A 1000 watt PSU that's only 40% efficient is only going to give you 400 watts. You've already said that Nvidia's site lists the cards as drawing more power than your PSU can deliver. As far as nothing happening, there is a very real chance your PSU will bite the dust if it tries to draw too much power. I would suggest looking into something 80+ certified starting at 650watts+ With the 80% efficiency that should give some leeway for capacitor aging. Look for PSUs that have the requisite # of connectors natively without adapters. Newegg lets you search by # of PCIE connectors, so it isn't too hard to find suitable PSUs.

 

Agree with above. There can be HUGE difference in supply output from different brands and model lines.

Technically, I think 850 would be enough for an SLI setup IF the PSU were of a good quality.

If it were a cheap PSU, then as it warms up and starts taking a load, it will drop significantly.

When building a system, the FIRST thing I make sure it has is a HIGH quality PSU. Look for the 80+ rating and maybe read a few reviews of PSU tests. You may be surprised at how some big names are not that great, and how a few unknowns are making very nice supplies for some builders.

 

buy a good power supply thats SLI rated, it will have two 6 pin conector for your cards

 

I need 4 6 pin connectors. 2 for each card

 

The adapters work fine. I would not hesitate to use them. IF the PSU was quality and big enough.