Anyway to disable Hyper Threading?

Has anyone figured out a way to disable hyperthreading? I don't really have a use for it and would much rather have a cooler laptop and longer battery life

 

Operating system is multithreaded by default and would run extremely crappy especially the modern ones like Win 7. It would be quite dumb to disable it for the claim of "no use". Got to remember the processor in m11x is a ULV and not a full mobile processor in case you missing on that. if u really want to save on battery there are some software out there that can allow you to adjust the efficiency of your cpu lower. cant remember what is it off my head thou. since i am happy with what it is on mine and in fact i would rather it be faster especially like with the use of TS from unclewebb

 

You know, that is a darn good question. Can you disable hyperthreading? I was playing around last night, and in msconfig you can actually set your CPU count at startup. So I set it to 4 and sure enough, boot up and got 4 (this is for the i7-720qm). What I couldn't tell is whether it was 2 phy / 2 hyper or 4 phys. So if someone can find an identifier for a hyperthread/logical vs physical then that may help. StevenX

What I am trying to say is that it may be possible to set MSCONFIG to startup with 2 processors, save config, reboot and then you have 2 processors only.

 

Yes I know that it's multithreaded, I'm not oblivious to the world of computers though. I disable HT on all of my desktops. Hyperthreading can actually decrease performance in non-optimized programs. On any of the desktop i7's, disabling HT can yield a 20-30% increase in max overclock as well as decreasing temps by roughly 10C.

 

He's talking about HYPERthreading, not MULTIthreading. Hyperthreading is what makes a CPU core look like two virtual cores to the native OS.

Typically, you disable hyperthreading in the BIOS. If the M11x BIOS doesn't have a way to disable HT, then I'm pretty sure it can't be done.

But even if you could, I don't think that disabling hyperthreading would really do anything for you on an M11x. Hyperthreading only causes a performance hit for programs that are VERY CPU heavy (specifically, programs that hammer the ALU) running in configurations where the processor affinity is not properly set. This situation happens in servers, but almost never happens in desktops or laptops.

And increasing max overclocks would be useless, because there is a hard cap of 166Mhz FSB that is set on the overclockability of the M11x anyway. And again, this would only benefit situations that are CPU-bound. So much of what you would do on an M11x will be either GPU-bound, or storage system bound.

 

The SU 7300 does not have Hyperthreading.

Intel® Core?2 Duo Processor SU7300 (3M Cache, 1.30 GHz, 800 MHz FSB) with SPEC Code(s) SLGS6, SLGYV

 

The i7 does

Intel® Core? i7-640UM Processor (4M Cache, 1.20 GHz) with SPEC Code(s) SLBMM

 

I dont know about battery life, but on my Samsung R590 i5-450m, I can disable hyperthreading in the bios, so i thought it would be interesting to run wprime with it enabled and disabled.

enabled 32m takes 23.94 seconds

disabled 32m takes 31.38 seconds.

 

Yeah, I want to disable HyperThreading, too. I do the same thing for my i7 930 desktop, and there IS no performance hit in games. I just get a 7-10C cooler running CPU.

 

How to disable hyper threading, by StevenX
1. Start -> Run -> type MSCONFIG <ENTER>
2. Choose the BOOT tab
3. Click ADVANCED OPTIONS
4. Click the box next to number of processors
5. Select 2 from the drop down list.
6. Select Ok
7. Choose EXIT AND RESTART.

Have a nice day.

StevenX

 

Already tried that and it kills your other physical core, so you have one real core that has a hyper thread instead of two phsyical cores and no hyperthreading.

As already stated, the reason for disabling hyperthreading is reduced heat output as well as the possibility of getting a higher OC/TB. Alot of applications and games will take advantage of a higher clock than an additional 2 threads.

I also disable HT on my i7's unless I know for a fact the app I'll be using is coded to take advantage of multi-threading.

I'm sure someone savvy could use modbin to edit an AW BIOS to unhide the feature to turn off hyperthreading.

 

Of course this makes perfect sense.............WPrime is specifically written to use multiple threads. Run SuperPi Mod and report back your results.

 

that's weird.. on my 720qm it kills the hyper threads first. Meaning when I change from no selection, to 4, I then get a boost of 12 physical. Are you sure it is killing the physical?

Thanks, stevenX

 

CPU-Z reports cores and threads so check with that program.

If hyper-threading is turned off, CPU-Z will report the same for cores and threads.

I'm pretty sure that this can only be disabled at the bios level.

 

That's exactly how I verified it when I tried it. I was initially happy when I looked at task manager, but CPU-Z said 'FAIL'

 

I have notebook and I can't disable HT. I turned off in msconfig-Boot 1 processor so now I have 7 threads. But I was very surprised! I opened Perfomance Monitor and saw all 7 "cores" working instead it was before. When all cores were enabled I could see that every second core (thread of a core) was in status "Blocked" and it was greay and only 4 were working.
I'm interesting is it good or not? Windows's index did not changed. I did what I did because I hoped that voltage will not be used for second thread and it will be used for better Turbo Boost but what if now it is disabled some features. Is it save?

 

unless you can disable from bios theres no way to do it

 

It also killed off the hyper threading cores first on my ASUS EP121, which normally has 4 virtual cores.

Steve, thanks for pointing out this tip as there is no option in BIOS to turn off hyper-threading on my ASUS EP121.

 

AgeKay: Can you post a screen shot of RealTemp with the Settings window open in each situation?

RealTemp 3.67
http://www.mediafire.com/?jibd769x6z7n0c8

In the Settings window is a value called APIC ID that shows how the cores and threads are organized by the bios. Most bios versions for most motherboards arrange these like this:

0 1 2 3

Thread 0 and thread 1 belong to the first core and thread 2 and 3 belong to the second core. Other motherboards arrange these like this:

0 2 1 3

So the first two threads belong to two different physical cores. When you disable two threads using the msconfig trick, you disable the hyper threads and are left with two physical cores as your CPU-Z screen shot shows.

I'm just trying to find out a reason why your CPU / motherboard is different than most. The majority of boards are like the first example so when you disable two threads you end up disabling the entire second core which isn't what most people are looking for. Interesting find.