Rendering threads

ADB wrote on 8/9/2007, 12:51 PM

The default number of rendering threads appears to be 4. VMS help says "For example, if you had a dual-processor hyperthreaded computer, choosing 3 would allow you to keep one thread available for other tasks while rendering."
I have a dual processor Pentium 4.
I downloaded a threading test application called "thread3r". It tests performance for various numbers of threads. I found that the performance was almost identical for 1, 3 or more threads but about 8% of that value for 2 threads !!
Does anyone have an explanation and suggestions as to why VMS threads should be set to anything other than 2 for dual processors ? Is there something amiss on my PC?

Comments

Ivan Lietaert wrote on 8/9/2007, 1:24 PM

Found this on the sony knowledge base. Perhaps it makes sense to you?
Vegas Video 3.0 and multi-processor PCs.
Question
Vegas Video 3.0 and multi-processor PCs. Does Vegas Video 3.0 utilize more than one processor on a multi-processor PC?
Answer
Vegas Video 3.0 uses many 'threads' while playing. Each thread is qualified to be processed on any available CPU. The system handles all of that for Vegas. Any time more than one thread is running on a multi-CPU computer, more than likely both CPUs are being used. So the system splits tasks between the two processors, even in an audio-only project. Dual processors also pay off when rendering DV. If Vegas Video 3.0 detects two or more processors, it compresses to DV on one thread and renders/composes video frames on another.