700w Enough For SLI?

[sygma]

Hi!

I'm looking to get a second 560 ti ( Gigabyte GeForce GTX 560 Ti Overclocked 1GB ) and run it in SLI with my MSI GeForce GTX 560 Ti Hawk 1GB. I have a Thermaltake 700w Litepower PSU, so will it be enough to run my two cards?

Regards
Sygma

 

[icebreaker125]

Yeah thats enough power to run a GTX 560Ti in SLI, its not a generic psu either so you're probably fine

 

[GreenDutchAlien]

I believe the psu only has only one pci express pin but i think you can make two of them with an special plug or something. It should be powerfull enough anyway.

 

[4745454b]

According to this thread here, you might have around 40+A on the 12v rail.

http://www.tomshardware.com/forum/273649-28-litepower-700w-5770-q9400

Lets say 42A. 42A * 12V = 504W. Let's assume you have a 95W CPU and take away 50W more for the board, drivees, etc and that leaves you with around 350W for your GPUs. The TDP of the 560TI is officially 170W, so 340W is needed for SLI.

So yes, technically you have enough power. What delluser didn't say in that power however that 65% efficient PSUs, and those that don't clearly state how much power is on the 12V rail shouldn't be used. Period. More so if this is a many years old PSU that you've been carrying over from build to build. Retire it, get a new one. If it did work, it won't for long.

 

[GreenDutchAlien]

Yep, and you don't have the hassle with making 8 pins from 4. ( get a 80+ certified )

 

[nforce4max]

700w is cutting it to short for comfort and wouldn't do it my self. At stock they run 160-180w each and fully overclocked a typical 950mhz to 1ghz gtx 560ti run about the same power consumption as a single gtx 570. Around 225w each so I suggest a more powerful unit or not overclock. At stock they should not be a issue but have to factor in the needs of the rest of the system.

 

[deweycd]

A 80+ efficient PSU at 700W would run this card no issue. However as stated you only have a 65+ efficient PSU which leaves you will less power. Buy a better PSU.

 

[sygma]

Its a new PSU, I only bought it less than a month ago.

 

[sygma]

Should I under-clock both the gpu's to run at reference speeds?

 

[phishy714]

Why would you spend more money on overclocked cards to then underclock them because of your PSU? What happens when down the road you want to upgrade and then you are stuck with a PSU that won't cut it, so you will have to spend the cost of a gpu AND a new psu all at once?

You said you JUST got the psu.. well return it.. use the money plus a little bit more to buy another, more effecient one.

Also - underclocking them will only lower the power consumption slightly. Not enough to make a real difference.

 

[sygma]

Because I got both the cards for a very good price. (lower than one reference card added together).


Also if I were to return the PSU and buy another, what would be recomended?

 

[GreenDutchAlien]

Corsair, Antec, higher priced Cooler Master, try to get an 80+ certified and stable single rail anyway. If you ever wanne sli ( maybe with a next system ) get at least 750W.