First of all, hi. I'm new to the teksyndicate website, but after watching so many awesome videos I had to sign up.
Now my question: I measured to total power consumption of my PC a few weeks ago, but that was with a non overclocked CPU. My system, with 1 SSD, 1 HDD an EVGA gtx 770 SC and an i5 4670k at stock settings, didn't consume much more than 300W of power under max load (measured at the socket) So I was fairly confident that I could add another 770 without any problems.GURU3D.com measured the card alone at 199W of maximum power consumption.
But now after the overclock (Core voltage is now at 1.195V btw.) and because I can't measure the power right now I am a bit anxious about buying the second card..... So, my PSU is a BeQuiet E9 680W, it is 80+ Gold certified, the brand is german and pretty high quality. Also, it has 4 +12V rails with 22, 22, 18 and 18 Ampere. So a combined 80 amps on the +12V rails. The PSU is also SLI/Crossfire certified, so every card would have it's own rail.
SO, would my PSU still be sufficient? I know that there are calculators, but pretty much all of them are from PSU manufacturers and blatantly lie about the Wattage actually needed to run your setup. I appreciate all kinds of help here.
After googling it looks like a single 770 draws about 300 watts at full load, (and that equals a chandelier with 8 old bulbs) :O that's a shit load of juice.
80+ Gold equals 87% efficiency at 100% load, so you can rest assure that your psu will be good up to about 590 watts.
Use this as the limit when checking if your psu is efficient enough, then just count using the manufacturers max power consumption of each component, and add a 20% margin to be safe.
Well, to be honest that is exactly not what I was looking for, I want to know if the system will run under real life terms. The Manufacturers specifications are always something ridiculous, like your card running at 98°C constantly. As I said GURU3D.com had an article about that specific card, and they made the estimate that this card, under 100% load only draws about 200W, which would be congruent to what I measured myself.
Under real life terms you're good as long as your PSU can provide 400 watts of constant power without overheating (and of course as long as your PSU has all the connectors it needs).
Okay, maybe the stuff I wrote was a bit confusing, but how much does overclocking increase the power consumption of the CPU? Because 410 W for both cards + 120 W for the processor + more than 70 W for mobo, hard drives and fans should work out and would still give me 80W of breathing room for the PSU. Or could that lead to an instable system?