Results: Power Consumption
We measure the power consumption of these graphic cards as described in The Math Behind GPU Power Consumption And PSUs. It's the only way we can achieve readings that facilitate sound conclusions about efficiency.
Idle And 2D Desktop
An 8W result is downright impressive, though we're puzzled as to how GeForce GTX Titan X uses less power than 980 in spite of three times as much memory and a far more complex GM200 GPU.
A closer look at the individual rails shows that the loads fluctuate periodically; the overall result represents an average of many ups and downs.
Ignoring professional applications and torture test scenarios, gaming is where we see the highest power consumption. The Titan X measures an average of 224W in this scenario.
Torture – Full Load
While Nvidia reports the GeForce Titan X’s TDP at 250W, it never actually reaches this figure under normal circumstances. In fact, not one of the usual stress test applications pushes the card past 247W. With the gaming loop average at around 224W, this typically leaves about 25W left for further overclocking. Sure, that doesn't sound like much, but we are working in the realm of hypothetical here.
The 250W TDP stated in Nvidia’s technical documentation is difficult to reach, even if you deliberately try to max out Titan X's power consumption. In normal usage scenarios, you'll see this board way under our observed ceiling. Arming it with one 8- and one 6-pin PCIe power connector seems like overkill, and this certainly leaves a lot of room for speculation about possible cooling solutions from Nvidia’s partners.
Last, but not least, Nvidia should be commended for limiting GeForce Titan X to 75W from the motherboard slot. Higher spikes, which we've seen from more mainstream graphics cards, don't show up at all. The dynamic load distribution across the rails works flawlessly.
Power Consumption Rankings
Reporting in at 9W, GeForce GTX Titan X’s idle power consumption is surprisingly, despite the 12GB of GDDR5 on-board. The reference GeForce GTX 980 surpasses it by more than half.
The GeForce GTX Titan X’s efficiency in gaming loads is really impressive. Also, something every car aficionado knows holds true here as well: there's no replacement for displacement. GM200 performs exceptionally well at a relatively low clock rate, doing wonders for its power consumption. As we know from many previous tests, Maxwell-based graphics cards overclock well but lose efficiency quickly, since gaming performance doesn’t necessarily scale well with frequency and power consumption at the high-end.
Once again, we see the restrictive power target at work during our stress test. This is really only relevant to targeted torture tests, though. It's simply a value we want to know, if only to better appreciate where the graphics card's limits are.