w860cu Disabling HyperThreading?

Please share the wisdom if anyone knows how to accomplish this. Thank you in advance.

 

It can be done. All you have to do is flash it with the W870's bios. You can download this here. This link contains the W860's EC update. Once done, you can disable HT in bios. You also get a nice overclocking feature if you have an extreme cpu and RAID support.

More about this bios here. Ignore the download links from that thread, as they contain the W870's EC update.

 

I confirm it works

also a good side effect of this bios is your computer is much more stable under windows 7 x64 than with the original w860cu bios.

 

Will this work with the 820QM?

 

Some games and programs work better with it off. I also noticed a slight drop in temps with it off too.

 

Yeah it works with the 820QM. That was my original CPU before I upgraded to the 940XM. The bios contains the same microcode as the W860 bios file.

 

Hi Chin, thanks for all of this. Sorry for being a pain but can you tell me where I can get the latest EC firmware? Also, I downloaded 2 versions of the bios update through both of the links you gave me (one from the other thread). As you can see one of them contains a couple of extra files. Which one should I use? Thank you

 

Use the bios file from here.

If you need a guide on how to flash the files, you can follow this.

 

oups i did update the ec with that bios.

but computer seems to be working just fine (except the fact the computer shutdown instead of restart when changing bios settings)

should i change the ec again?

 

See here.

 

Updated my 4shared link to the XMG7C Bios. It includes the W860CU's current EC update. This is for the W860CU ONLY.

Hope this makes it easier for others who want to update to this bios.

 

I was all about disabling hyperthreading until I found this:



If you do any other types of work, this is something to keep in mind.

 

I don't understand the fascination with disabling hyper-threading in the Core i7 processors. It is said that some programs operate faster, but my limited tests so far do not confirm this; in fact, they show a significant performance penalty. It does show that, with hyperthreading disabled, the processor uses slightly less power and runs somewhat cooler, which tends to reinforce the observation that it's doing less work. For example, using CineBench 10, my Sager 8760 with a 920XM returns a multi-core score of 13,508 with HT enabled. With HT disabled, the score drops to 11,567, a 14.37% reduction. Using wPrime (32M test), with HT enabled, the 920XM completes the test in 11.182 seconds; with HT disabled, it requires 14.172 seconds to finish, a 26.74% performance hit. Simulating 940XM performance by raising multipliers and TDP to 940 levels results in higher scores, but the same reduction in performance with HT disabled.

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What am I missing? Where (and how) does disabling a portion of the processor's computational structure improve performance?

 

It is true that you get better performance with it on, however with some legacy games and programs, their code isn't efficient enough to make use of the extra cores and causes compatibility issues. That's why it's good to have an option to enable/disable it. For example, GRID can't make use of more than 4 cores. The game freezes at the menu if you have an i7 with HT on. You have to modify the xml code to get it to work with more than 4 cores.

 

Thanks, ChinNoobonic. So compatibility not performance is the attraction. Glad to finally have it explained.

 

Disabling HT could be useful for people without an extreme CPU. Since we cannot use ThrottleStop to adapt TDP, we have to accept the fact that the CPU will not use Turbo Boost if the TDP is equal or over 45W (for the 720, 740, 820 and 840 that is). The question is if by disabling HT the TDP when running 4 threads falls below 45W which would mean that Tubro Boost would activate. I think I'm going to make some extensive testing this weekend. Also: does anybody know what is the factor that allows ThrottleStop to set TDP/TDC? The CPU itself or bios suport for overclocking? This could mean a performance boost if you only run programs that use 4 or less threads (Games), but that is what I want to find out.

 

Well, that's worth exploring. The 820QM in my M15x suffers from the 45W TDP limitation. With 4 cores/8 threads under full load, Turboboost works but is limited to about 14.4x instead of the 15x advertised. With the 920XM, it's not the ability to increase TDP/TDC that allows it to fully utilize the default multipliers; it's that the stock 55W TDP provides sufficient power for the purpose (barely). I will be interested in the results of your research and testing.

From comments made by Kevin (Unclewebb), author of Throttlestop, it is my impression that it is the CPU that determines whether T-Stop can manipulate TDP/TDC, rather than the bios, which is consistent with my experience. ThrottleStop works as well on the 8760 using the Sager or Clevo bios as it does when running the partially unlocked mySN bios. But we don't have to guess. He will share how it works and explain what governs it operation.

 

Umm... HT seems to make no difference, it even seemed the CPU used more power with 4 threads (50W max)... this is weird. Gonna test it out a bit more in the next days. Also how are you able to get Turbo Boost to work with 8 threads, mine will not work and the temps should be alright. What are your temps? Mine where 76 - 79°C on the cores, a bit to high for my taste, but then again it was full load with 8 threads (+ full load on GPU) for like 15 mins. CPU drew 60W (which might be the answer, 60W on CPU, 75W on CPU = 135W, more than the 120W PSU would allow).

 

Well, TB just works, though not as well as I first thought. I'm not doing anything to trigger it or facilitate it. Using wPrime v1.55 to test, the 820 runs at 14.4x for the duration of the 32M test (short speed test). During the longer 1024M stability test (about seven minutes for the 820), it begins at 14.4x, but slowly leaks down to about 13.7x. Core temps reach a maximum of 72-73*C, and maximum CPU power draw is about 50W. I suspect that the multiplier leakage may result from temperature throttling in an effort to reduce CPU temps, which may be unique to Dell (the 820 is in an Alienware M15x).

 

OK. I'm done with the first test. Here is the comparison between HT on and HT off:

The result is rather surprising. Turning off HT has no effect on the multiplicators, increases power consumption but decreases temps on the cores... (core temp may simply mean that the room temperature is lower, but it should be similiar to what it was when I ran the tests with HT on). I'm pretty disappointed... could the bios have some influence? Is it maybe buggy? All tests were done with the same bios... I think I'm going to switch back to the newest W860CU bios - really no point in disabling HT except for compatibility. However, I don't understand how you can get higher oc with HT disabled, if disabling it actually increases power consumption - at least for me.

 

i used to play grid a lot a few months ago and ive never had problems with my 720qm. was this fixed in a patch?

 

Just add core affinity to the shortcut, problem solved.

 

Well, how do you do that, JohnnyFlash? And when do you use it?

 

@Daniel Hahn - agree with your conclusions. I'm not sure I understand all we know from the tests, but disabling HT seems counter-productive unless, as ChinNoobonic suggests, you encounter a program which just cannot run with HT active. +rep.

 

Here's a decent explanation.

It gets complicated when you get into combinations, because you don't add numbers to designate multiple cores, you change the number to one above the number cores you have. Each number is a different combo.

ie. My Dolphin shortcut looks like this: C:\Windows\System32\cmd.exe /C start /high /affinity 50 C:\Emu\Dolphin\Dolphin.exe

/affinity 50 = Cores 5 and 7 only.

Every number between 7 and 50 is a different combination of the 8 cores, it can get a little confusing if you want strange combos like: Core 0, 4, 5 or something.

/affinity 9 on an i7 would be core 0 and 2. (Remember that odd cores are HT)

 

Thanks, get's a little complicated, but interesting. Excellent reference to the How-to Geek source.

 

Thanks. I'll definitely rerun the tests, this time I'll use wPrime 32MB and/or 1024MB test. Also I'll add a third run with the newest bios this time.

Thats great info! Is there a way to limit the ammount of memory a program can use in a similiar way? I always wanted to play Act of War again, but it only works with two cores and 2048 ram, so what I had to do was use msconfig and reduce number of cores two 2 and amount of memory to 2048MB... but you have to restart each time you want to change those settings.