Question About Rendering Threads

surferj45 wrote on 11/1/2006, 8:19 AM
In Preferences under Video the default setting for rendering threads is 4. I found that changing this to 2 in Vegas 6 seemed to speed up my rendering times. Is this logical? I now have Vegas 7 and wondered if I should change this to 2 again. Can someone explain what this setting does? I only have a single core AMD 2.5 GHz Athalon processor if that is relavent.

Thanks

Comments

grh wrote on 11/2/2006, 6:09 AM
Having more threads means having to do more work to parcel out rendering tasks, more work to put pieces back together (presuming the rendering is accomplished per-frame, rather than a pipeline) and of course switching tasks in the OS to let the threads run. Fewer threads cuts down on this overhead.

More is not necessarily better. For scalability you want to match your software config with your hardware config and with a single-CPU system, you don't want very many threads.
Jayster wrote on 11/2/2006, 6:22 AM
The user manual says that increasing this number to anything higher than the number of processors available does not increase performance. So if you have a single core, non-hyperthreaded machine, 1 is the highest. With hyperthreading, 2 would be the highest for that machine.