After Effects CS5.5 - GPU rendering in RAM Preview

questions about practical use of Neat Video, examples of use
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aaronkondziela
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Joined: Wed Nov 30, 2011 6:57 am

After Effects CS5.5 - GPU rendering in RAM Preview

Post by aaronkondziela » Wed Nov 30, 2011 8:28 am

I just installed Neat Video this evening, and I've been experimenting with all the settings and evaluating performance. One thing that I found was that GPU-accelerated Neat Video rendering was not working in RAM Preview - it would use CPU only. This took me an hour of adjusting settings to figure out what was going on, so I figured I would share in case anyone else runs into this.

To make use of the GPU in a RAM Preview, you must set the Fast Previews button in the composition viewer window to "Open GL -- Always On". You also need to activate Open GL in the After Effects preferences. If set to Interactive or the other settings, Neat Video will not make use of the GPU for calculations in most cases.

I determined this by watching a GPU and CPU usage meter installed on the system (Windows 7). It was quite obvious which was being used.

Hopefully this saves someone some time, or finds its way into the instruction manual!

I love Neat Video so far - it works miracles. Thank you for making a fantastic product! :D

- Aaron

NVTeam
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Post by NVTeam » Wed Nov 30, 2011 12:00 pm

Aaron,

We could not reproduce such a behaviour in AE so far.

From the developer standpoint, NV does not use any of AE's GPU related functionality, so changing AE's parameters should not affect NV's use of GPU.

How exactly do you measure the GPU load? What video card is it? Is it the one driving the display or the display is connected to another card?

Thank you,
Vlad
Image Image Neat Video team
noise reduction for video and photos

aaronkondziela
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Joined: Wed Nov 30, 2011 6:57 am

Post by aaronkondziela » Thu Dec 01, 2011 3:29 am

I thought the same thing, and found it odd. I figured that NV used it's own GPU code, and before I saw this it seemed that if anything, disabling AE's GPU features would leave more resources for NV. Instead, it was the opposite.

For measurements I'm simply using a GPU Meter and CPU Usage desktop gadgets for Windows 7. I compared the activity I saw during NV's GPU tests in the preferences.

NV used the GPU as expected when rendering - I only saw this odd behaviour during RAM Previews.

I should also mention that, while experimenting with various settings, GPU RAM allocated to both NV and AE, GL rendering on and off, etc, that there were one or two times that NV *did* use the GPU with other settings than what I listed previously. But, I could not reproduce it. I thought that there may have been some kind of resource contention between NV and AE, but I couldn't figure anything out that was consistent other than the above.

NVTeam
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Post by NVTeam » Thu Dec 01, 2011 9:36 am

I am wondering if there are perhaps two video cards, one integrated into CPU and another is discreet, and the discreet one may be switching off when idle (AE's GPU features are disabled and are not using it) and not switching on fast enough to do preview rendering by NV. To check this idea I would need more details about the hardware side. Could you describe it please?

Also, please try to set NV to render using GPU only (in Preferences > Performance tab). Will it still work? Will it be slower?

Thank you,
Vlad
Image Image Neat Video team
noise reduction for video and photos

aaronkondziela
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Joined: Wed Nov 30, 2011 6:57 am

Post by aaronkondziela » Wed Dec 14, 2011 12:09 am

There is one video device, a discreet GTX560Ti. Nothing on the motherboard. I occasionally get different behaviour - I just tried it and it worked one time with interactive opengl turned on, then it required it set to always on after that. Odd! I'm not sure what else to check, but I'd be happy to help if you want me to gather more information. Please note this isn't causing me any problems, I can work just fine. Just a curious situation.

I have NV set to GPU only, since performance is slower if I enable GPU+CPU for my video.

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