Processes run on 1 cpu (in HT system) only

[hansrijf]

Hello,

I have this strange problem, without any changes made to system, os or bios (as far as I know anyway): all of a sudden the processes in the taskmanager run on 1 CPU only. I have hyperthreading turned on in the BIOS but they all run on CPU 2 only.

Is there a registrysetting to enable/disable a cpu on a HT system? In devicemanager there are no problems, "both" cpu's show up in the devicelist.

Who can help?

Thanks
Hans

 

[hansrijf]

bit disappointed...

 

[LordOfLA]

If you could run applications on a second cpu with HT I'd be wondering where my second chip came from. HT = 1CPU that runs 2 threads at a time.

If windows doesn't schedule tasks to the "Virtual" cpu it obviously doesn't need to.

 

[ShepsCrook]

Yeah, just because Windows shows there are two processors, it doesn't mean you have 2 processors. This is true with the Pentium 4 HT processors. The processor like mentioned before shows a "Virtual" CPU along with a "Physical" CPU. There is only 1 CPU on your machine, 1 Core. But runs 2 threads much like a dual core would. Does this perform equal to a dual core? The answer is NO.

 

[Brad]

wow, what a top that was.

 

[LordOfLA]

Dual core will happily run more than 2 threads faster than HT as will single core CPU's that are not netburst based

 

[ray_gillespie]

I thought he meant that his HT CPU is only showing up a single graph on his CPU usage history. A HT CPU should show up as two graphs as Windows treats it as two.

 

[hansrijf]

I thought he meant that his HT CPU is only showing up a single graph on his CPU usage history. A HT CPU should show up as two graphs as Windows treats it as two.

This is correct. Even though my BIOS is setup as "hyperthreading enabled" under taskmanager the programs only run under "CPU 1" and nothing runs under "the other CPU" although "both CPU's" are visible as a graph.

Specially for MS Flightsimulator I want to have FS9 run under "CPU 1" and the rest of the few necessary programs under "CPU2"

Thanks so far

 

[ShepsCrook]

ohhhh.... I'm sure you've tried Disabling HT in the bios, then starting windows, then restarting, then enabling HT. Otherwise, try updating your bios.

 

[LordOfLA]

you cant dictate what cpu stuff runs on. Thats down to the windows thread scheduler. I twill balance loads if it deems it necessary, but it knows thats not too helpful with HT anyway.

 

[hansrijf]

ohhhh.... I'm sure you've tried Disabling HT in the bios, then starting windows, then restarting, then enabling HT. Otherwise, try updating your bios.

Yes tried this too. Didn't work....

It is not such a big problem, everything runs well anyway. Would just like to know why it happens.