Regarding your question "so the topic of this thread mainly is, how would a computer with 2 physical 3.40ghz processors impact in the performance?"

First, I am not an expert on this topic, and certainly I don't know if a second _physical_ processor would be any different than having more cores.

The video capture task is handled by Windows operating system, but, of course, once the video data is actually captured, Isadora does the rest. Isadora is not multi-threaded at this time, not that this is going to make a significant difference if you're putting that video through lots of effects etc. So, to sum up 1) the actual act of capturing from the camera may be improved by more CPUs, etc. because the Windows subsystem may move those tasks to other processors, 2) the effects processing in Isadora (meaning actors like Desaturate or HSL Adjust, etc.) will not benefit because it is not multi-threaded.

Hopefully that helps; I'm sorry that I can't give a better answer.

And, usb does consum CPU resources.

anybody else knows about this?

anyway, and going back to my original question, I know that the main problem is the processes that I am applying later, since I have tried the patch without a live capture, but with a movie player, and the performances problems remain.

so how would a computer with 2 physical 3.40ghz processors impact in the performance?

Graphics NVIDIA NVS 5100M graphics with 1 GB dedicated DDR3 memory

The Live capture is not the issue. the issue are all the processes that comes afterwards.

What kind of video capture card do you use ?

This changes a lot how heavy it is.

Can you describe your actual machine ?

With 2.8gHz Core2Duo I used to capture 2 x 720x576 streams, with a very low impact on performances.

I was using internal dedicated video capture cards ( like blackmagic intensity )

Best

Mehdi