Right we installed the cards so let's have a look at how much power draw we measure with these graphics cards active and running.
The methodology: We have a device constantly monitoring the power draw from the PC. We simply stress the GPU, not the processor. The before and after wattage will tell us roughly how much power a graphics card is consuming under load.
Our default test system is based on a power hungry Core i7 3960X/ X79 system. This setup is overclocked to 4.6 GHz (core 1.40V). Next to that we have energy saving functions disabled for this motherboard and processor (to ensure consistent benchmark results). On average we are using a bit more than a standard PC due to higher CPU clock settings, water-cooling, additional cold cathode lights etc.
We'll be calculating the GPU power consumption here, not the total PC power consumption.
GPU STRESS TEST
GeForce GTX 780
GeForce GTX 780 2-way SLI
Mind you that the system wattage is measured at the wall socket side and there are other variables like PSU power efficiency. So this is a calculated value, albeit a very good one.
Above, a chart of relative power consumption. Again the Wattage shown is the card with the GPU(s) stressed 100%, showing only the peak GPU power draw, not the power consumption of the entire PC and not the average gaming power consumption.
Here is Guru3D's power supply recommendation:
GeForce GTX 780 - On your average system the card requires you to have a 550 Watt power supply unit.
GeForce GTX 780 2x SLI - On your average system the cards require you to have a 800 Watt power supply unit as minimum.
GeForce GTX 780 3x SLI - On your average system the cards require you to have a 1000~1200 Watt power supply unit as minimum.
Though we do have some reserves calculated into our recommendation remember this; if you are going to overclock the GPUs or processor, then we do advise you purchase something with some more stamina. The minute you touch voltages on the CPU or GPUs, the power draw can rise real fast and extensively. There are many good PSUs out there, please do have a look at our many PSU reviews as we have loads of recommended PSUs for you to check out in there. Let's move to the next page where we'll look into GPU heat levels and noise levels coming from this graphics card.
Gigabyte GeForce GTX 960 G1 Gaming 4GB review In this review we check out the 4GB version of the Gigabyte G1 Gaming GeForce GTX 960. The GTX 960 is the mainstream product that we figured has too little memory, will this 4GB version resolve our co...
Nvidia GeForce GTX Titan X Review We review the GeForce GTX Titan X. Now it surely hasn't been a long wait as in-between the introduction announcement and launch there have been two weeks. But yeah, the 12 GB beast has arrived. Initi...
Palit GeForce GTX 960 Super JetStream review In this review we check out the Palit GeForce GTX 960 Super JetStream. This product is in the top 3 of best GTX 960 cards as it is performing the fastest, it is the most silent one, and it has just go...
ASUS GeForce GTX 980 Matrix Platinum review We review the ASUS ROG GeForce GTX 980 Matrix Platinum. This product has been designed for the true aficionados that sub-zero cool the product in order to shatter a benchmark or two. For the more reg...