PSU + UPS + SLI ?

Hello! I hope you can help me !


I read people saying that 2 GTX 580 in SLI can work in a 750watt PSU without overclocking anything, is this true ? or it will damage any components ?

Will a UPS of 1000va handle the 750 watt PSU with SLI? and If that psu can't handle the SLI will a 1000watt running SLI cards work normally in a 1000va UPS ?


Thanks!

Well i can answer half your ?, a 1000watt yes if gonna be the best for a GTX 580 SLI setup. anything bellow 1000. you asking for trouble. as for the UPS thing, i havn't used a UPS yet so i wouldnt know

As for a 750w psu running 2x gtx 580's I'm not completely sure. When I was running 2 my wattage load was between 450-600 watts with a slight factory overclock though I was using 1250w enermax psu at the time.

As for the battery back up, I recently upgraded my psu to an AX1200 when I recieved my 3rd 580 and I noticed in the manual that for a 1200w psu it is recommended to run at least a 1500w ups.

Honestly I was running a 900w ups with a 1250w psu for 2x 580's for almost a year, and though I ditched the ups when I got the third card I'll be willing to bet you could make your setup work as long as it is one sweet 750w psu. I'd have to say I wouldn't recommend it though. If the strain of the cards overworked the psu there is a chance of a surge ruining your gear.

Step one is to figure out the wattage of the 580, specs say its max draw is 250. So your two 580s will draw 500 watts. That leaves on 250 for your board and chip. It should work ok but your cutting it very close.

Second thing to look at is the amperage that the 12v rail of the PSU can put out. Finding the amperage of the GTX580 is not easy because the manufacturer does not always publish it. Reveiws I red put it between 25-30 amps. So you need an amperage of 60-70.
Unlikely you will find a 750 watt PSU with that type of amperage. You will probabbly need a 850 or greater.

Finally question about the UPS. The Voltage amperage of the UPS is not as important as the wattage. An easy way to look at it is, the PSU can supply 750 watts of power to the PC but because it is not 100% effecent it can draw up to 10 % more from the wall, so your 750 PSU can draw 825watts. So your UPS must have a wattage of 825 or greater. The UPS voltage amps should be at least 20%-40% greater than the wattage, so an 825 wattage UPS should have a Voltage Amp of around 1000va.

If you know the max watts that a PSU will draw and the voltage level, then you can easily calculate the amperage. Amps = Watts / Volts
So a single 580GTX with a max 250W load is equal to 20.83333333 amps.

wooww thanks for replies!!!! that was fast!

Ok so here are my specs

intel 2600k
2x580gtx msi twin ii
asus p8z68
1 dvd writer
1 sata II hdd
psu corsair tx750 v2 bronze certified http://www.corsair.com/power-suppl [...] upply.html


I'm still thinking what case to buy so I don't know how many fans i'll be running, i was thinking in a CM storm eforcer, a HAF or a elite 431plus

I believe I need the UPS because the power here is a bit unstable, my actual surge protector blinks when loses power from the wall for a milisec and shuts down my actual pc... maybe If I buy a more powerful surge protector instead the UPS ?

I'm not sure if it's safe to plug it direct to the wall...


And about the SLI I tested some online calculators and says it will need a 735 watts psu but I'm not really sure, I would like to run it for some months till I can upgrade it I didn't expect to get a second 580...

There's a way to check if the PSU is doing well while using the SLI in a game ? like the wattage and amp use with any software or tool?

$1000 worth of gpu in a 431($50)case lol!
You might want to spend $100+ on a case with plenty of room and airflow.
At least a HAF 922 = 932 Advanced or X would be better.
And you might want to get an 850W psu for the difference in cost of a 750W.
I know i would.