htt

[ssprncvegeta]

i understand how it works, but why is it slightly slower for games and benchmarking? or is that not true?

[ninthebin]

I have never heard of it being slower for such things - it either helps a little or does nothing. Any links to the benchmarks you seen this on?

:santa2:

[NookieN]

I have never observed a slow-down in a single task on my system with HT-enabled vs disabled. Of course with multiple tasks there will be a slow-down in any individual task, but that slow-down would be worse on a system without HT/SMP.

The only time you might see performance degredation due to HT is if you have tasks running at idle priority (or background tasks). The problem is that the Windows scheduler allows low priority tasks to use CPU time on the second virtual processor. That means that a low priority task can steal time from a high priority task when HT is enabled.

The only reason benchmarks would be noticeably slower with HT-enabled is if another program (e.g. Folding, servers, spyware) is running in the background.

[ssprncvegeta]

Originally posted by NookieN
I have never observed a slow-down in a single task on my system with HT-enabled vs disabled. Of course with multiple tasks there will be a slow-down in any individual task, but that slow-down would be worse on a system without HT/SMP.

The only time you might see performance degredation due to HT is if you have tasks running at idle priority (or background tasks). The problem is that the Windows scheduler allows low priority tasks to use CPU time on the second virtual processor. That means that a low priority task can steal time from a high priority task when HT is enabled.

The only reason benchmarks would be noticeably slower with HT-enabled is if another program (e.g. Folding, servers, spyware) is running in the background. ic. that makes sense. but what if u set the priority to High or Realtime, would it only work on that one tast then if there were other progs that might be using cpu processness?

[NookieN]

Raising the priority might help a little, but for the most part there's no way to convince Windows to not give time to the low priority task without just stopping the task.

As an example, I usually have Prime95 running at low priority on my computers. When I do video encoding on my HT-enabled box, the encoding is 8-10 fps slower with Prime95 running. If I stop Prime, the encoding goes at full speed (which is 20-40% faster with HT-enabled). On an HT-disabled box, Prime has no impact on the encoder because the encoder always has higher priority.

[ssprncvegeta]

sweet. what speed overclocked to what

[NookieN]

Just a 3.06 @3.3GHz. Nothing too exotic.