Divx 5.1 and multi-processor systems

Has anyone run into problems using multiple processors w/ divx 5.1 and vdub 1.5.4? I only achieve cpu utilization of ~50%, leading me to believe that for some reason only one of my processors is being used...

filling up the cpu 

For that matter, can someone point me to some vdub settings that will let me max out my cpus? I routinely (w/ divx 5.0.5) ran only 65-70%, which was somewhat frustrating...

Well, there's a couple possibilities that I can think of... 1) I don't have a real 2-proc system, but I have two virtual with hyperthreading enabled on my P4. I sometimes observe what you describe above, especially if I'm using the computer for other tasks. However, if I leave it alone for a minute, VDub will start to eat up processor time, well above 90% for both v-procs. 2) It's possible, but unlikely, that processing power isn't the 'limiting reagent' for your encoding specs. That is, if you're doing fast encoding, it may be that your HD or system bus isn't feeding the CPUs fast enough to keep them at 100%. But, that's probably not the case unless you're well above 30 fps. You can easily set the processing priority of VDub, but that's not really the way to go - that just gives it priority over other processes currently running, but doesn't 'force' it to use more CPU time. One last item is that you might want to check for updated drivers for your motherboard - initial dual-CPU boards didn't split the data buses as well as they do now.

I was under the impression that the encoding itself happened on only one processor, but the additional filters (resize, noise reduction, etc.) were run on the other processor. If overall CPU utilization is low, I think it's because the encoding takes much more time than the filtering. Try lowering the resolution of your output video, so the encoder is doing less work, but the resizer has to do almost the same amount of work. This will probably boost overall CPU utilization. Or, you could add a noise filter, and see if that increases utilization. If so, you should see the same number of frames encoded per second, because the encoder is still the bottleneck, but because of your second processor, you get noise reduction "for free". On my dual MP1600+, with 5.05 slowest or 5.1 standard, a 640-pixel encode will use 70-80% CPU, while a 480-pixel encode will be 95-100%. With 5.1 slow or slowest, a 640-pixel encode will only use 50-60% CPU. Divx 5.1 doesn't take as much advantage of dual-processor systems because it's slower, am I correct? Or is the encoder itself multiprocessor-capable? Edit: clarified which Divx versions were used to get the CPU utilization %'s.