[EMAIL PROTECTED] wrote:
Brendan, Why is that?
It's the nature of hyperthreading. You don't actually have a second CPU core with hyperthreading, that's just how it appears. Inside the CPU there are multiple execution units. When you're running a program there are times when some of these units that go idle. They're idle because the kind of work they do is not available or data needed to run is unavailable. If a second process/thread is active that could be run on those idle units, you may get a performance benefit. Conversely, if you're running two copies of the same algorithm, you may create resource contention for the same missing data and the same execution units. You will also take a performance hit from the context switches as the two processes are swapped back and forth. HT can be a real win when you have multiple processes (or threads) doing different types of work. That's generally not the case of multithreaded encoders.
-Brendan _______________________________________________ Cinelerra mailing list [email protected] https://init.linpro.no/mailman/skolelinux.no/listinfo/cinelerra
