Thanks for sharing that and props for Toms for starting a new power measurement standard. :thumbsup:
I'd be curious what the 290x consumption looks like in a similar measurement. I have a watt reader but it's so slow that I wouldn't have guessed the peaks are so high and often.
Pretty interesting..
Yep, this is an interesting part of the cards debut. Important for PSU selection IMO, you'll need more than you'd otherwise be led to believe by the cards TDP numbers.
From Tom's,
To illustrate, let’s take a look at how Maxwell behaves in the space of just 1 ms. Its power consumption jumps up and down repeatedly within this time frame, hitting a minimum of 100 W and a maximum of 290 W. Even though the average power consumption is only 176 W, the GPU draws almost 300 W when it's necessary. Above that, the GPU slows down.
I'm seeing power numbers indicating various degrees of power savings based on different presentations amongst the reviews. Toms appears the most in depth. Is the average power use way down vs other and is the peak draw something to be concerend with for PSU selection or is this just normal for a card rated at X TDP to have peak draws almost 2X TDP at peak? I'd have been tempted to run the 970SLI (145w TDP) on as low as 550w or 650w PSU, wonder if that still a good idea. Worked fine for R9 270 xfire (150w TDP).
Interesting that the R9 270 has a 150w TDP with one 6pin while the 970 has 145W TDP with 2x6pin. In real world use which card is drawing less peak and average?
Hopefully someone digs in and uncovers the real story of what's going on and explains more fully what were seeing there at Toms. I think i'd probably be wanting 750w for 970SLI and 850w for 980SLI despite those ultra low TDP ratings of the cards.
What are the official recommendations for PSU's for 970 SLI and 980 SLI?
Tom's goes as far as to say that under certain circumstances the 2x6pin connectors on the cards might not be enough!
Stress Test Power Consumption
If the load is held constant, then the lower power consumption measurements vanish immediately. There’s nothing for GPU Boost to adjust, since the highest possible voltage is needed continuously. Nvidia's stated TDP becomes a distant dream. In fact, if you compare the GeForce GTX 980’s power consumption to an overclocked GeForce GTX Titan Black, there really aren’t any differences between them. This is further evidence supporting our assertion that the new graphics card’s increased efficiency is largely attributable to better load adjustment and matching.
Power Consumption Under Max. Load
Gigabyte GTX 980
Windforce OC
GeForce GTX 980
Reference
GeForce GTX 970
Reference (Emulated)
Gigabyte GTX 970
Windforce OC
PCIe Total 237.63 W
233.64 W
188.96 W
192.46 W
Motherboard 3.3 V 0.98 W 2.63 W 2.16 W 2.15 W
Motherboard 12 V 41.07 W 48.35 W
48.38 W 48.36 W
VGA Card Total 279.68 W 284.62 W 239.50 W 242.97 W
The values above have potential consequences for the everyday operation of these graphics cards, as they represent what can be expected when running performance-hungry compute-oriented applications optimized for CUDA and OpenCL. The reference card’s two 6-pin PCIe power connectors start looking a bit out of place in this context, as they might just not be enough.
Emphasis mine. I suppose this would be a bigger deal to GPU miners, but intersted how it might play out in 99-100% constant gpu stress gaming scenarios with compute (4k or other) vs 1080p power usage scenarios.
http://www.tomshardware.com/reviews/nvidia-geforce-gtx-980-970-maxwell,3941-12.html