I'm with Black_Zion here...
Look at my system specs in my below sig.
With 100% load on the CPU and 100% load on my graphics card, my system pulls a total of 371W from the wall. Since the power supply is not 100% efficient, the system is actually using apporximately 300W - 310W.
Picture to prove it: http://imageshack.us/a/img833/6612/img0108pn.jpg
Keep in mind, this is with my CPU overclocked to 4.1GHz with all core pegged at 100%, and my 7970 overclocked to 1150MHz / 1480 MHz (I believe during that time) with +20% power and at 1.175V.
No way adding a second card is going to go over the 850W range. I'd say it be in the range of 500W-600W (650W ish if overclocked).
Or this, I had THREE Radoen HD 5850's running on my system a few years back...using the same Corsair TX850 power supply.
That graph looks like overall system power draw. If you check all the review sites (Anandtech, Legitreviews, Hardware Canucks, etc) there is NO 100% accurate method to measure JUST the power draw from graphics cards.
I repeat, there is NO 100% accurate method to measure JUST the power draw from graphics cards.
The card is connected to your motherboard's PCI-E slot...which supplies power as well (a max of 75W)...then you add in the additional PCI-E 6-pin / 8-pin connections. They can provide a max of 75W and 150W respecitvely, but the card may not need the full amount.
I also know a few guys from Steam's Users' Forums --> Hardware & Operating System section...
Borg_7_of_9 is using two Sapphire HD 7970's, with a i7-2600K overclocked to 4.8GHz, with a couple HDD's and SSD's. His entire system is water-cooled, so hes got a bunch of fans and radiators. Hes using a Corsair AX850W power supply. (Pictures included). http://forums.steampowered.com/forums/showpost.php?p=19879116&postcount=3
HL2-4-Life has got a i7-3960X, three HD 7970's, a few 2133MHz RAM modules, a few hard drives...and he's running a SeaSonic X-1250W. (Go down the list...you'll find his sytem there) http://forums.steampowered.com/forums/showpost.php?p=19879271&postcount=8
FX-8350 @ 4.8GHz // ASUS Crosshair V Formula 990FX // Sapphire Vapor-X HD 7970 + Dual-X HD 7970 // Thermaltake Frio w/ push-pull (using Antec Formula 7 Nano-Diamond + Cooler Master JetFlo fans) // 8GB (2 X 4GB) G.Skill RipJawsX 2133MHz // Corsair TX850 850W // Corsair Force GT 120GB SSD (OS) // Kingston V200+ 120GB SSD // WD Caviar Black 1TB // Windows 7 Ult x64
02:34 AM by