msconfig - number of processors?

Question about "number of processors" option in the msconfig boot/advanced options? With hyperthreading it shows 8 cores on a quad. If I set it to 4 processors will it run 2 cores with hyperthreading or basically disable hyperthreading?

 

What would make you want to 'tweak' this setting? (Let windows manage itself...).

This won't disable anything - only a BIOS setting would change these - but I have seen this make Windows not boot at all...

 

I do not know for sure, but based on the way \affinity works in Windows, I would assume that it will use the first 4 available processors which means you get 2 cores with hyperthreading. If you need to disable hyperthreading for a specific application, you can use \affinity to make it run only on specific cores. If you want to do it globally, it is best to do it in the BIOS.

 

Problem is Clevo BIOS does not allow to turn off cores or hyperthreading.

 

Is this setting not for a multi processor system, not for how many cores you have, best leave it alone.

John.

 

Processor or core, doesn't matter. They're treated as the same in Windows.

 

They're not. Each is quite different.

First 4 are physical cores, last 4 are logical cores. Changing any settings within windows will do almost nothing, if you "turn off" the last 4 you will neither lose hyperthreading nor physical cores, it will just leave them "unused" and will not allocate anything to them. Nothing is disabled, it still has 8 logical cores, throttling and speedstepping is untouched.

There is literally no practical or theoretical gains in disabling them, unless you are allocating different programs/processes to certain cores to spread out the work load.

Are you absolutely 100% sure there is no BIOS option to disable hyperthreading? It would be the first i've ever some across without the option.

 

I understand they are not technically "disabled" but they are unused by the OS, and understand there are 4 physical and 4 logical, which is why I was asking though what was disabled. And I wasn't asking for gains or otherwise. I was simply trying to compare gaming performance trying to mimic a dual core CPU vs a quad core CPU. Which I did.

In any case you must not be very familiar with Clevo BIOS's (see youtube video below of np9150). They are very sparse, although frequently the options are there and if someone has enough gumption will create their own BIOS to enable the features that are hidden, as Prema and I did with the Sager NP6110 / Clevo W110ER.

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This is really the best I can come up with. Disable Hyperthreading in the Windows 7 registry - Super User According to one poster, disabling hyperthreading is a bios only affair. I do remember for instance on an old P4 system that was a single core with hyperthreading, simply selecting only one processor disabled it (of course). Beyond that I really can't help you.

 

Remember to "Unpark" your CPU cores before doing 4 processor limit on msconfig to bypass HyperThreading. Actual way to disable HT is via BIOS but incase you are using laptop that don't have that feature, the unpark core and msconfig is the only way.

I actually gained some performance by using 4 cores. Killed micro-ters in few games and apps like WinRAR benchmark much higher score.