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Core i7 running on only 4 threads?

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June 4, 2009 12:31:51 AM

When I check in task manager under performance tab (or any other CPU utility for that matter) I'm only seeing every other thread working. This is while running FSX or whatever. Is this normal? P6T Deluxe mobo all cores enabled and hyperthreading enabled.

More about : core running threads

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June 4, 2009 12:35:07 AM

Do any programs actually use 8 threads?

If a program only runs on two cores w/o HT (vast majority do), is that = 2 threads?
June 5, 2009 2:50:32 AM

To answer your questions; mabye 2 and yes. A little research answers the first question, a little common sense seems to answer the second. An answer to a question is nearly always a little quicker than a question to a question. But thanks for the questions, they questioned my question and answered my question all at the same time! If you have any more questions just let me know. I'm here and happy to question them. Sham
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June 5, 2009 3:15:26 AM

FSX does not use HT. And although it uses multiple cores ( with the patch ), it is still effectively limited to 2 main cores and most importantly clock speed.
June 5, 2009 3:32:43 AM

I know. Nero 9 does. Beyond that, we move into program obscurity. I should've named the mabye 2 that do in my reply. I didn't know the rest of them don't in my original post. What little activity you see happening on the ''nonworking'' threads is the OS, which utilizes HT.
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June 5, 2009 3:34:32 AM

Go into the BIOS, and turn on Hyper Threading.
June 5, 2009 3:36:51 AM

Its on. I'm pretty sure my question was answered first try by Bluescreen Death. But feel free to let me know if I may be missing something.
June 7, 2009 1:39:31 PM

Bluescreendeath said:
Do any programs actually use 8 threads?

If a program only runs on two cores w/o HT (vast majority do), is that = 2 threads?

All programs run on all enabled cores.? Everything I run SEEMS to be picked-up by all 4 cores. Did I mention Its an i7? OK. Tell me this. Is FSX running on one thread on each of four cores, or two threads on two of four cores w/HT?
June 7, 2009 2:49:02 PM

FSX can run on upto 32 threads, the no. of cores doesn't matter if it had one core with 32 threads per core it would use all of those threads, if it had 64 threads per core it would run off 32 of those.
June 14, 2009 10:15:13 AM

Helloworld_98 said:
FSX can run on upto 32 threads, the no. of cores doesn't matter if it had one core with 32 threads per core it would use all of those threads, if it had 64 threads per core it would run off 32 of those.

Look. I'm seeing 4 cores. 8 threads. 2 per core. 1 of the threads per core (a total of 4 threads) run at 100% usage which is equal to 50% total cpu usage under load. The other thread on each core more or less just sits there. I would have thought that all 8 threads would run congruant. Getting the cpu to go above 50% is not impossible but nearly impossible. Even with heavy loading and gaming. I was able to get it to top out 4 threads (50% cpu usage) and then see the other 4 threads actually move...barely. They went up to a whopping 2.5% each. 10%. Bringing it to 60% total cpu usage. NON OF THIS SEEMS RIGHT! My SIMPLE question is this. When any of you, owning a QUAD core with EIGHT threads, run FSX and pull up task manager and look at the cpu usage history under performance, do you see FSX using 4 threads or 8 threads? And dont tell me to turn on hyperthreading. Its enabled in both the bios AND the Nvidia control panel. Yes?...No? I'm not JUST talking about FSX. Its just a good example.
September 7, 2009 5:37:53 PM

Hi, I found this topic when I was looking up some info on a similar topic. I could reproduce the same results in taskmanager on my core i7 920. But only now. I recently had to re-install my OS and this time I thought about giving windows 7 a try. When running in windows vista, I could game with all threads more or less evenly under load. Now, under windows7 it's the same 4 threads active, and 4 threads seemingly doing nothing at all. I too am wondering why that is so. I haven't had the the time yet to install other games, but this is a first thing about windows 7 that caught my eye. (Although I have no idea if it actually matters if it's windows7 or vista. I'm just posting my findings.)

Grts,
Chris.
September 7, 2009 5:58:43 PM

Its not windows.....I'll be back.
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September 7, 2009 6:29:49 PM

hmmm..... i may not have an i7 yet but i do have the HT p4. About the only thing i can say is try running multiple cpu intensive programs to see if all 8 thread will run.

If so then then FSX may not be capable of running all 8 core.
If not then maybe it's the cpu.

weather it's the turbo boost, speed step, or some program on the computer, i don't know what would be causing something like that.
September 7, 2009 9:12:25 PM

FSX, as well as most other programs, doesn't support hyperthreading. Just multiple cores. So if you were to disable ht in the bios, my theory, is that you'd see 4 cores fully running, rather than 8 cores/threads, with only 4 of them half running. I've never tried. If you had a single core cpu with say, 4 threads with hyper threading enabled in bios then you'd see 4 cores/threads with one core running at 25% (3 cores/threads would just sit there idle.) With ht disabled, you'd see one core at 100%. One game that I believe takes advantage of hyperthreading is, Trackmania Nations Forever. Its free... Anyways...I'm no expert. so if anyone sees anything wrong with my thoughts, please let me know. That's why we're here...Right?
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September 7, 2009 11:45:44 PM

Sham_ said:
FSX, as well as most other programs, doesn't support hyperthreading. Just multiple cores. So if you were to disable ht in the bios, my theory, is that you'd see 4 cores fully running, rather than 8 cores/threads, with only 4 of them half running. I've never tried. If you had a single core cpu with say, 4 threads with hyper threading enabled in bios then you'd see 4 cores/threads with one core running at 25% (3 cores/threads would just sit there idle.) With ht disabled, you'd see one core at 100%. One game that I believe takes advantage of hyperthreading is, Trackmania Nations Forever. Its free... Anyways...I'm no expert. so if anyone sees anything wrong with my thoughts, please let me know. That's why we're here...Right?

There's no such thing as a program that supports multi core but not hyperthreading. Hyperthreading appears to the OS and to programs exactly the same as if the CPU had twice as many cores. Any program that supports an 8 core CPU would also support a 4 core with hyperthreading (although the 4 core with hyperthreading won't perform quite as well).
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September 8, 2009 1:39:27 AM

The issue may be that instead of using how many threads are avaliable, its just hardcoded to run up to 4?
a b à CPUs
September 8, 2009 2:08:32 AM

Could be, though it would be rather odd, since I use FSX and it has used more than 4 threads before.
September 8, 2009 4:30:49 AM

SP1 disabled hyperthreading for FSX due to thread collisions. ......■Since the release of SP2, the "Not Using Hyperthreading" statement could be false.
Tweak FSX for 8 Threads
As it turns out, some members are able to 'unlock' all 8 'cores' (or all 8 threads) by making some changes to the FSX.cfg file.

■Change the "AffinityMask" entry to "AffinityMask=255" if you are a core i7 user, there are reports that this may help with the problem.
■You can also set it to 254 to leave 1 core free for programs other than FSX that require CPU, such as TrackIR, etc.
■Members report that using AffinityMask=255 helps with loading speed, but not in game stuttering!
Here is a link to the AVSim Forum post [Link], and more information about AffinityMask from Phil. [Link]

■Members on AVsim report the the method that BEST helps stuttering & FPS is AffinityMask=15, With hyperthreading off.
You can find the FSBN here. http://forums1.avsim.net/index.php?showtopic=241915
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September 22, 2011 5:57:54 PM

This topic has been closed by Mousemonkey
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