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New Power Supply for SLI?

Last response: in Graphics & Displays
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February 7, 2011 8:08:49 PM

Ok this is a Graphics / PSU question.

Here is the Power Specs for my GTX 275
Maximum GPU Temperature (in C) 105 C
Maximum Graphics Card Power (W) 219 W
Minimum Recommended System Power (W) 550 W
Supplementary Power Connectors 6-pin x2

I currently have a OCZ 750w Power supply.

If i go into SLI mode do i need twice the power like a 1100w PSU? or does the 750w push enough to handle 2 cards?

I'm not sure if the Wattage is divided up or if it's pushed out equally i guess thats the difference.

I have 1 DVD drive and 1 Sata Drive other then my video cards. No other on board cards or plan for them.

More about : power supply sli

a b U Graphics card
February 7, 2011 8:20:44 PM

You'll be fine with 750W supply. You don't need double the power, usually just 100W more max.
a b U Graphics card
February 7, 2011 8:24:29 PM

No, you don't need a 1100W. The 550W minimum power requirement is for the entire system with one card. For SLI power requirements take that system power requirement and add the maximum graphics card power for the second card and you get a figure around 775W.

I would have to say that you may be able to get away with a 750W PSU, but it could be close. An 800W-850W would give you a greater margin of safety.
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a c 106 U Graphics card
a b ) Power supply
February 7, 2011 8:35:19 PM

You should be fine with your current PSU. As long as you're motherboard supports SLI you'll be good.

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a c 212 U Graphics card
a c 124 ) Power supply
February 7, 2011 8:37:42 PM
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Using the PSU calculator linked below, I come up with 598 watts w/ a single 275 and 787 with twin cards (920 CPU, OC'd to 3.75,1 SATA, 1 DVD, 5 USB, 1 firewire, 10% capacitor aging).

http://www.antec.outervision.com/PSUEngine

At the least, I'd get an 850 watter that gets a 10.0 performance rating at jonnyguru.com .... in alphabetical order

Antec CP-850*
Antec SG-850
Corsair AX-850
Corsair HX-850
XFX Black Edition 850

* requires compatible case

The XFX is going for $90 on newegg at the moment, after $20 promo code and $40 MIR.
February 7, 2011 9:18:45 PM

Really? I got the OCZ one as a reccomendation that OCZ made really great PSU's. I will go ahead and look into a 800+ PSU, but i'll try the SLI for now with 2 cards to see if it glitches any. If i have problems i'll pop one out and wait for the new PSU.

a c 153 U Graphics card
a b ) Power supply
February 7, 2011 9:23:33 PM

You might be able to get away with a 750w PSU of amazing quality, but probably not with OCZ, only a couple of their lines of PSU were good, and the rest were junky, so without knowing what exact line of PSU you have I can't recommend anything either way.
a c 499 U Graphics card
a c 1098 ) Power supply
February 7, 2011 10:35:45 PM

The only OCZ 750 Watt Power Supply Unit that I know of is the OCZ750FTY model from the Fatal1ty Gamer Series.

It has a Maximum Output Current of 18 Amps on each of the four +12 Volt rails.

The Maximum Combined Power of the four +12 Volt rails is 650 Watts.

The OEM is Sirtec.

Yes, there are definitely better 750 Watt power supplies available.
a b U Graphics card
a b ) Power supply
February 7, 2011 10:50:20 PM

OCZ is pretty high end, yes, they did have some bad times, but they have really cleaned up. I would say go 800+, but who knows, OCZ is pretty high end and does normally give you what they tell you they will, if it is a newer version. My OCZ PSU is great. The first series such as, STealthXstream, ModXstream, etc. were not good, but now they say for example StealthXstream 2 which is normally pretty good.
a b U Graphics card
a b ) Power supply
February 7, 2011 11:05:21 PM

Look on the back of your PSU and there should be any area were it tells you the power of the 12v rails, under that it should tell you how much the 12v rails will supply. My 600w supplies 580w off the 12v rails, which is pretty good. Yours should probably be something around 700~730w on the 12v rails.
February 8, 2011 2:22:03 AM

OK my mistake it was a 700w


http://www.newegg.com/Product/Product.aspx?Item=N82E168...

OCZ StealthXStream OCZ700SXS 700W ATX12V / EPS12V SLI Ready CrossFire Ready Active PFC Power Supply

Many people reported it burning up, my computer runs pretty much non stop and havn't had problems in over a year. I do clean my pretty regular as i'm in a dusty enviroment though.

Prob won't push this PSU with it's history and just get a new one at this point..




a b U Graphics card
a b ) Power supply
February 8, 2011 2:29:49 AM

If I were you I would upgrade your GPU because of your CPU. A phenom ii x2 265 isn't a real CPU, maybe a Athlon ii x2 265? I would at least get an 800~850w PSU before I would SLI two of those.
February 8, 2011 2:34:36 AM

Best answer selected by c911darkwolf.
February 8, 2011 3:27:22 PM

haha, i typed that in wrong.

Should be
AMD Phenom II X4 945 Deneb 3.0GHz Socket AM3 125W Quad-Core Processor

i'll fix that.

Due to the Shady history with OCZ's stealth model i am going to get a new PSU first.

Hostile, i posted a different thread and the majority said i would get a better performance form 2 of the gtx 275's vs say a gtx460 or the like?

Using the website provided by Jack. I put in 10% aging and got MIN PSU for 680. Still with OCZ's feedback on Newegg.
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

going to grab me a Antec first.

Thanks All!
a c 271 U Graphics card
a b ) Power supply
February 8, 2011 3:56:59 PM

This topic has been closed by Mousemonkey
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