I was recently asked how to turn off a CPU core in a dual-core computer. Depending on your need, there are actually 3 ways to accomplish it.
The first method disables cores for the whole system. The second turns them off for a specific program. Finally, you may just want to shut off those fake Hyperthreading cores.
Turning off CPU Cores in Windows
This method literally turns off cores in Windows. Just go into msconfig. See the image below.
Solid Tip: Go to Start > Run > msconfig > Boot tab > Advanced options > Number of Processors
Disable Cores for Specific Programs
If you only want to disable cores for a particular application, you can set your “CPU affinity” in task manager.
Solid Tip: Press Ctrl+Alt+Del > Start Task Manager > Processes Tab > right click desired program > Set Affinity
Disable Hyperthreading Cores
An Intel dual-core has 4 “logical” cores and a quad-core has 8 “logical” cores, thanks to Hyperthreading. Most people think Hyperthreading is a joke. It also makes your CPU run hotter, and 99% of users will never see any benefit if it exists.
You can disable these “logical” cores in the mainboard BIOS. This option should be listed as “Hyperthreading [Enabled/Disabled]” in your BIOS options. This is for Intel CPUs only. AMD does not use Hyperthreading (and Hyper Transport has nothing to do with that).
Is there any way to set cores off-limits universally to all but a specific program? Say I have a quad-core machine and a very important and high-CPU application that I can’t have halting. I can set affinity for that program to specific cores, but how do I keep other applications from using those cores without manually setting affinity for every process in the machine?
To summarize, is there any way to tell Windows “I only want [this] to run on [these cores] and nothing else is allowed to”?
Actually, you are in luck. You can try freeware programs like “THG Task Assignment Manager” or “Edgemeal Get and Set CPU Affinity“. They can set multiple affinities at once.
I have not used them or others like them (which means I am not endorsing them), but they are helpful for people who run F@H, for example.
Or this link… it’s largely in French, but there’s always Google Translate
http://translate.google.com/translate?u=http%3A%2F%2Fwww.bill2-software.com%2Fprocessmanager%2F&sl=fr&tl=en&hl=en&ie=UTF-8
What if I want to disable a specific core? I have one core of my quad core that runs about 10 degrees hotter. it is the third core, so I’d want to run only cores 1,2,4.
If you want to do it across the board, then you have to try some 3rd party program or you are stuck manually setting it for every program.
Go to Bios, CPU Configuration, switch 3rd core to OFF and press F10 to save and exit.
Edgemeal Get and Set CPU Affinity < that is exactly what ive been looking for for months, perfect, thanks
AMD doesn’t use HyperThreading, but it does use a paired core architecture for Bulldozer and beyond where each pair of logical CPU cores shares some computational units and caches, and thus the OS has to be aware of them in the same way as it has to be aware of HT cores.
I recently turned off my cores from 8 to 1 and upon tebooting the device it started acting up. I cannot access any of my documents despite windows trying to run diagnostics. All the machine displays is that it has run into a problem and windows will try to fix reapeatedly..kindly assist
Tried some dif changes mainly to get an old game called Call of Juarez to work, it has issues with 8 cores but works with 1 to 6 cores. Tried running just the game with a set amout of cores but didn´t work, Then i tried a couple of different settings with either windows 10 controlling tru boot settings or directly tru bios, and i found that running an 8 core AMD processor at 1 core made the whole platform unstable and not working due to overload. 3,5 and 7 cores also showed some strange disturbance.
But running with 2,4,6 cores the platform was stable,always ran (2 cores 1+2, 3+4, 5+6, 7+8) (4 cores 1+2+3+4, 3+4+5+6, 5+6+7+8) (6 cores 1+2+3+4+5+6, 3+4+5+6+7+8)
When i tried disabling inbetween a row i ended up getting unstability during stress tests. Might be just my platform but if not it seams that there linked in pairs and not working correct if not both are active or diabled.
And for Andrews problem, i would gess it´s due to overload, try run with 2 cores and i bet it will work, or try run 1 core + failsafe start with minimal setting to lower load on core.
The original post here is seven years old, so a lot has changed since back then (so with 8 cores, it’s a whole new ballgame).
However, I remember we had an article specifically for Call of Juarez – a great game- and getting it running. It has some issues with black screens or crashing so check that article out using our search bar.
With AMD Bulldozer/Piledriver/excavator, each pair of cores shares one FPU and cache. If you disable one core of the pair, chances are that you disable that FPU and some of the cache, so the other cannot use it and is trying to. So, as you have shown, each odd core needs its even to function properly. So, if you must disable it must be in pairs like core 0/1, 2/3, 4/5, 6/7. This is my logic as to why it causes instability when disabling only one core.
my core is 2 and 4 logical processors but i did something and it has been disabled to 1 core and 2 logical processors . is there any soloution . my laptop is lenovo ideapad 110 15isk with amd radeon r5 m430 and Intel (r) core(TM) i7-6498DU CPU @ 2.50GHz. what do i do ?