GTX 470 using only 10% power on playback
 

I recently installed the GPU meter gadget on Windows 7 so that I could monitor the usage of my GTX 470 card while editing and was shocked to see only 10% being used while playing footage from my Canon t2i loaded with all kinds of FX. Is that normal? I thought that the Mercury Engine would really tax the GPU to its limits but that isn't happening. Am I doing something wrong? Just so you know, I'm getting the yellow line above the clips on my timeline so I know Mercury Engine is activated, but then why isn't the card being fully used. Alternatively, the CPU meter (which I also installed) was going nuts, showing almost 90% usage. If that's the case then do I even need a Mercury Engine compliant graphics card? It seems the CPU is doing all the heavy lifting.

(FYI: when playing Battlefield 3 the GPU meter shows up to 100% of the graphics card being used)

I'm building another system so now wondering whether I should even invest in a compliant graphics card or just allocate that money into more CPU power.

Any thoughts?

Re: GTX 470 using only 10% power on playback
 

Here's why:

It depends on which FX effects and the number of FX effects are applied. A video editing machine in MPE GPU acceleration mode uses both the CPU and the GPU - and not all FX effects are GPU-accelerated (in fact, some of the effects that you're using don't use GPU acceleration at all). Games, on the other hand, use the GPU very heavily but do not use the CPU as much.

Re: GTX 470 using only 10% power on playback
 

Thanks Randall, and yes I did think of that, so that's why I piled on a multitude of effects which included GPU accelerated ones as well as regular CPU intensive ones, just to get a bit of variety going. Even then it was only the CPU that showed any usage. The GPU stood quiet. You would expect all GPU accelerated effects to tap into the GPU's processing power, but it was the CPU that was being pushed instead.

Re: GTX 470 using only 10% power on playback
 

Also, you have to know that Maximum Render Quality (MRQ) is always active on those encodes that use the MPE GPU mode. But in software-only mode, MRQ is disabled by default. So, if you don't have an MPE GPU-supprted card, you're forced to use software-only mode - and either your renders will be of significantly poorer quality or the encodes will take unbearably long (say, 12 hours for each hour of video processed) even with the very fastest CPU on the market.

Re: GTX 470 using only 10% power on playback
 

I'm not sure about this, but I think that mixing effects can also affect the use of the GPU. I had applied to all the clips fast color corrector, which is GPU enabled. In exporting in AME my GPU meter was near 100%. I didn't like the softness of the result, so I added a little unsharp mask, which is NOT accelerated, and the export went extremely slow and the GPU meter hardly registered. Realizing unsharp mask was not accelerated, I just used the sharpen effect (accelerated) instead, and lo, back to 100% GPU.

I surmised that if there is an effect that is not accelerated, then the export falls back to software MRQ, even if there are accelerated effects applied too. Since then I only use accelerated effects.

I could be wrong (probably)....

Re: GTX 470 using only 10% power on playback
 

I think David is right.

Peter

Re: GTX 470 using only 10% power on playback
 

the answer is really simple : the GPU just has that much in reserve. all the effects you applied simply require only a small amount of the GPU's time. thats good, it means you can do more layers with more FX.

h264 formats are decoded on the Cpu, so yes they will be working hard to decode that codec, depending on your config.

s