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core i5-520M - Is there a way to deactivate HT?

idata
Employee
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I'm wondering if is there any possibility to disable HT in mobile core i5?

I've got a i5 520m in one laptop and when I compare its rendering performance with my 3 years old c2d X9000 2,8GHz, the results are surprisingly bad for 520m.

IBM ThinkPad T61p, 8GB RAM

Penryn X9000 2,8GHz 6MB

Toshiba Tecra S11, 4GB RAM

core i5 520m 2,66GHz(with turbo) 3MB

1min 10s3min 28s

I remember from my previous experience with ht in Pentium 4 that is some cases the cpu with ht runs out of internal resources, which causes significant performance drop in comparision to same cpu with disabled ht. i5 520m has little cache and I assume that in my case it might perform more effectively without virtual cores and running extra threads.

I've looked online but couldn't find any useful information regarding my question. Disabling 2 cores in Windows MSconfig turns off one physical core and BIOS has only virtualisation, multicore and turbo settings.

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John_S_Intel
Employee
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Disabling HT requires BIOS support. Some OEMs provide you with an option to disable HT, but it sounds like this option is not available for the Toshiba* Tecra S11 platform. Do you have the lastest BIOS from Toshiba?

I am not aware of any application that runs better with HT disabled rather than enabled, and I doubt that disabling HT would address the kind of performance difference you are seeing. I think BIOS question and the performance issue is something you may need to bring up with Toshiba.

John S.

 

Intel Customer Support

 

*Other names and brands may be claimed as the property of others.
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idata
Employee
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JohnS --> http://software.intel.com/en-us/articles/intel-math-kernel-library-intel-mkl-intel-mkl-100-threading/# 5 http://software.intel.com/en-us/articles/intel-math-kernel-library-intel-mkl-intel-mkl-100-threading/# 5

werez Try setting the affinity of the software to use one thread per core, perhaps by using Taskmanager. This should give you a good idea of how the software would run without HT.

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