GPU acceleration messes up my preview and render

marcel-vossen wrote on 2/7/2012, 6:37 AM

Hi there,

I'm using Vegas pro 11 (64 bit), built myself a superfast i7 2600 / 16Gb system with a Gigabyte GTX 550 Ti graphic card and I installed the latest drivers for everything.

I noticed though that the preview window often starts to shake and blink in a very uncontroled way when I enable the 'GPU acceleration of video processing' feature. This is esp. the case when I start a second instance of the program BTW.

I also noticed that in a projects I'm trying to render now, the rendered video also has this shaking and blinking, in a way that is so severe that its absolutely unusable.
When I open the project in Vegas the preview looks okay as long as I don't have a second copy open, but the rendered video is a total mess.
When I turn off the feature and render like that, the rendering goes well.
The project has about 8 3D layers of flying movies in a cloudy sky.

Does anyone know what this could be?

Comments

Diamond12a wrote on 2/12/2012, 3:20 PM

I can't tell you why it is happening, but it is a bug. I have reported this to tech support:

Hello - A new bug was introduced with version 511 of 64 bit Vegas 11- strange distortions occir with GPU acceleration set to on, and rotation is used in pan/crop.

Here is an example of the distortion with gpu acceleration on:

Here is an example with gpu acceleration turned off:

This is also present in the newer version 521 build.

Express wrote on 2/23/2012, 11:43 AM

I had similar preview/editing issues.
Currently using VP11 521 and a GTS 250 video card (tomorrow will move to a GTX 560)

I could not edit for more than 2-3 minutes without preview messing up - green bands at top and bottom with static in the center - or the preview window would get 'stuck' on a couple of frames - would not show anything else.
Restarting VP11 would fix it again for another 2-3 minutes.

Turning off GPU acceleration completely eliminated those editing problems.
I then updated to the 295.73 NVIDIA driver, left acceleration off edited for about an hour with no issues.
I turned acceleration back on, and so far (a few more hours) I experienced one split second green screen which did not linger or cause any other apparent issues.

Current bottom line for my editing issues:
The 295 NVIDIA driver seems to make a difference (same with turning off GPU acceleration) - not a big deal as the GTS 250 isn't that great of a card- but rendering does take about 30% more time without GPU acceleration.

Note: the improvement I've experienced is for Editing/Preview only: rendered files still have flicker (showing fragments of other frames) with GPU turned on / No flicker (noticed so far) with it turned off.