Downloading texture data from GPU performance hit

General TouchDesigner Discussion
1

I have a file where a TOP is being sampled via the TOP to CHOP which works as expected and is fast etc.

however when I pipe the video stream being sampled out to another TD process via SPOUT and do the same thing again along side the first process I get a huge performance hit in touch process #2 labeled as “Downloading texture data from GPU”
I have it set to “next frame” in both processes.

Any clarifications as to why this happens with the second one? Is it due to certain nodes needing to download GPU data mid cook?

Would the shared mem nodes in commercial alleviate this problem?

Thanks!

2

Hi there. Sorry for not catching this until now.

I am not sure whether this will help you, but we have noticed on some machines high CPU usage that seems to be related to the NVIDIA GL/DX interop functions used for Spout where one CPU core can be running at 100%.

So if you have NVIDIA graphics, have a look at “Threaded optimization” in the NVIDIA control panel and set this to “off”. It also seems to be inter-related with Vertical sync and it is important to have Vertical sync on as well.

Lynn Jarvis
spout.zeal.co