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I have 3 GHz Pentium 4, and it's not best for playing full HD videos. I noticed, that when I'm playing full HD video, only 50% of my cpu is used, so only one of virtual cores is doing it's job on full HD video and the other one is idle. Sould I turn hyperthreading off, to get all 100% of power available for film?

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up vote 2 down vote accepted

No, don't turn it off. HyperThreading doesn't cut the processing power available to a logical core in half. 50% of the CPU used with HT on means a logical core is fully loaded, while the other is free.

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And that's the problem, isn't it? Film is beeing rendered only by one thread, so the other core doesn't do the job. – Filip Dec 19 '10 at 15:24
The CPU is doing the same amount of work whether you have HT turned on or off. When you have HT off, that amount of work is 100% of capacity. With HT on, you're doing the same amount of work but the processor could be doing more if it had more threads to work on. It's like having a 10 gallon tank that's 100% full vs. a 20 gallon tank that's 50% full: same amount of water, but the 20gal could hold more if you had it. – Stephen Jennings Dec 19 '10 at 15:38
Okay, I understand now, thx a lot! :) – Filip Dec 19 '10 at 16:22

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