Talking about highend cards mostly (Titan X, 980, 980 Ti, etc), I think I recall reading something about the fans will actually turn off at low temps.
 
With that in mind, does anyone know the actual power draw from these cards at idle?
 
I have a few Powered PCIe x16 risers from my mining days.  I could rig up an amp meter and really test that out.  But, I hate to invest into a card like that if the idle isn't much lower than my existing Titans.
 
TL;DR
 
This is mostly for a GPU Grid I am building that will sit mostly idle.  I've carefully have planned the 12C/24T system that currently idles at 41W measured at the wall when not in use.  
 
I'll pull one of my Titans during my upgrades and will measure that number precisely.  The powered risers allow for a completely isolated circuit to do just that.  I just hate to buy a Titan X or 980 Ti if the idle isn't much different.  (I LOVE my Titans!)

Perfect!

Wow, wasn't expecting that. And I knew the AMDs had higher power consumption as well, but not that high.

Really wish I could disable the GPUs at idle on an C612 chipset. Oh well.

Thank you!

bgeery
I you using the Multi Display Power Saver feature of NVIDIA Inspector?  I save about 30 watts on a single 970.

The GTX 970 only uses 10 or 11 watts idling with multiple monitors in the first place. I have no idea how you could "save" 30 watts. Your card is now generating electricity?

I don't see any mention in the original post about him using multiple monitors; so I am not sure if your advice is otherwise helpful.

I think you guys are talking about consumer-grade LGA1150 stuff. Good to know they have those options for the on-chip HD4500 GPU and alike CPUs.

As I mentioned above, this a Xeon C612 chipset with 12 cores (24 threads) on a single chip. Those consumer options aren't available (no on-die GPUs to switch to, no monitors connected).

So far I am running a mix of 1x Titan and 2x R9 280x passing through to different VMs. When I installed these, my idle consumption went from 41W to 68W. Not bad actually with 3 GPUs. But, still higher than I would like. Surprised to see the R9 280x not pull very much.

I tried disconnecting the fans on the R9 280x and Titan to see what kind of power draw they had - it wasn't much, like less than 1 Watt if I could even measure that.

So, "idle fan turn off" would be nice to save fan usage/dust over time I think. Not for power savings at idle as the usage is so minuscule.