Hi guys just finally went for a SLI setup I have a older I72600@4.6ghz and was using a 780GTX with a Be Quiet 750w PSU ive got everything working perfectly and am very impressed so far with the second 780, however the PC or rather the PSU I think as its become very loud when gaming or benchmarking is way too loud for comfort! So to my Q what should I be using that will quieten my pc and allow me to use my new sli 780 setup? Makes and wattages suggestions please and if you can answer asap as I want to order the item if I need it before 4pm! Many thanks TcM
My Rig (i7-4770K OC'd to 4.5GHz and SLI 780s with a little OC but no extra volts) needs the following power: Idle - 100W 100% CPU only (just Prime95) - 230W 100% GPU only (just Furmark) - 670W 100% CPU and 100% GPU (Prime 95 and Furmark) - 760W (measured with a power monitor from Maplin) So I think you'd be wanting an upgrade PSU-wise... To be safe I'd go for at least 800W but maybe a little more...
The simple answer would be if the PSU has 2 lots of 6 plus 2 rails then it will be man enough for the job.As an example on my Thermaltake tough power 775 I had CPU, mobo etc. Plus SLI GPU's a triple water cooling loop and 17 fans plus 2 fan controllers, ram cooler and all the lighting at once and it never missed a beat, I never even heard the fan on the PSU spin up to high speed where things where getting a bit stressed.. (Have a look at the pics in my build log for Saturday Night special and you will see what I mean) So unless you're a complete benchmark hooligan, the chances of getting everything running flat out all at once are pretty slim. So a decent 750 watt PSU will be more than adequate for your needs.
Did you take your PSU's efficiency into the equation? I agree 750w is a little close for comfort. OP: you may even want higher that 800 if you want silence and longevity. Gold rate PSU's tend to be quieter as a general rule as their components don't run as hot, but you'll want to check reviews to be sure how each model performs. That might be an ok general rule but my PSU for instance has 4 rails, 2 for PCIe 6 plus 2 but it's only 500W. It might work with lesser cards but 2x 780's is out of the question. With George's measurements above, you have to remember that Furmark won't even clock up to full speed on a 780 so it actually uses significantly less than the full amount of power when compared to say the tessellation tests in Kombuster. Playing Crysis 3 on that PSU just may be too much. I'd say 250W for each card (more if you intend to use a custom bios) around 150W (generous I know) for the rest of the system plus an extra 200W headroom so that the components aren't running at full tilt when stressed.
Not in those numbers - that's the amount drawn from the wall. The PSU is a Seasonic X-1050 and so Gold rated (or ~90% efficient).
So it's about 684W, but like I said GPUz won't even pull the max amount out of a 780 (it did with my old 670 thought)
