Do GPU's always use max power in game?

[Arkatakor]

I'm leaning towards this (see title) being a stupid question so my preliminary answer is that GPU's only consume as much power as they need even when in game. I would be grateful if someone else confirmed this though.

I am running 1020p and got suckered into getting an overkill ASUS Radeon R9 290 4GB DirectCU II OC GPU (not 290x). This GPU is normally made for higher resolutions however I purchased this with future proofing in mind.

The issue i'm having is this:

The ASUS Radeon R9 290 is power hungry (some reviews claim it nears the 400W mark at max output). The GPU box itself says that one needs a MINIMUM 750 Watt PSU. I have a EVGA Supernova G2 850W PSU. Normally I would feel safe, however I bought into 2011-v3. As some of you may know, CPU's for 2011-v3's are considerably more power hungry than their predecessors (140 watt TDP). Following are my specs:

Spoiler

• 
  GPU: ASUS Radeon R9 290 4GB DirectCU II OC (R9290-DC2OC-4GD5)
  MOBO: ASUS X99-DELUXE
  CPU: Intel Core i7-5820K, Socket-LGA2011-3
  RAM : 4x Crucial Ballistix DDR4-2400 SP QC - 16GB
  HD: Seagate Barracuda 2TB
  PSU: EVGA Supernova G2 850W
  CASE: NZXT Phantom 410
  HSF: Noctua NH-U12S

I am not sure if this is a safe setup: I'll be playing Battlefield 4 and Alien Isolation on highest settings, however on 1080p. Again i'm gambling that since the GPU will not run at full capacity to render 60fps on 1080p, therefore, the power consumption should not hit anywhere near the maximum that it can normally consume.

Can anyone confirm this?

 

[Bossyfins]

At most, average power draw would be 600

 

[Eximo]

They aren't any more power hungry then other CPUs from the X series. 130W and 140W have been fairly common.

GPU does use more power then other available cards, but is well within the capabilities of your power supply to handle.

Those peak measurements are just that, peak. Average load should be much lower then even what a lot of PSU calculators will tell you. The capacitors in a power supply are meant to handle precisely that. Which is why the recommendation is to get power supplies with capacitors like yours that are of high quality.

 

[burdenbound]

Your 850W PSU will be more than enough, I wouldn't worry about it.

 

[Arkatakor]

I appreciate all the assurances of my choice of PSU (I had researched it well before purchase). I certainly feel more assured that despite my choice of chipset and high end HSF, I am still within safe boundries.

It would still be interesting to know if this GPU would consume less power while running 1080p games, considering its really designed for 1440p.

 

[Eximo]

Depends on your settings.

If you turned V-sync on at 1920x1080@60Hz or limited your FPS to 60 then it would do the work required to render that output and no more.

If you were to do the same at 2560x1440 then it would require more of the GPU's resources to produce 60FPS.

If you leave V-Sync off it will render as many frames as possible given power and thermal limits. So there you would see a difference in the output of FPS at the same power output.

 

[Arkatakor]

Yes, in my research to answer my question before posting here, I came accross quite a few posts that spoke about turning v-sync on; though I have a hunch that this is enabled by default, Either way, when i'm all set up, I will make sure that v-sync is on at 1920x1080@60Hz. This should limit the resources used by the GPU which is exactly what I have been aiming to achive. Thanks again for your input