Disabling Hyperthreading hangs Windows Vista

I have Vista Ultimate installed and I installed it having HT activate.
Now I am interested disabling HT, because it works better to run processes
not prepared for multitasking.
If I disable HT from BIOS, then Windows Vista stops booting just when the
progress bar (starting windows) should start.
If I run in safe mode, also hangs after loading some drivers.
The only way to get windows vista to restart again is enabling again HT.

How can I disable HT and get to run Vista again?

thanks

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http://windowshelp.microsoft.com/com....vista.general

On Sun, 5 Aug 2007 10:54:01 -0700, HectorziN <> wrote:

>I have Vista Ultimate installed and I installed it having HT activate.
>Now I am interested disabling HT, because it works better to run processes
>not prepared for multitasking.

who in the world told you that ? And where are you getting these antique programs that will actually install on a hyper threading machine that won't work ?

>If I disable HT from BIOS, then Windows Vista stops booting just when the
>progress bar (starting windows) should start.
yeah.. And you'll probably see a lot more instabilities if you continue.

>If I run in safe mode, also hangs after loading some drivers.
>The only way to get windows vista to restart again is enabling again HT.
>
>How can I disable HT and get to run Vista again?
Why ? Upgrade the software. Use that hyper threading.. Use the multi tasking.
I think the machine's already told you it's not going to work with no HT.
--
more pix @ http://members.toast.net/cbminfo/index.html

Who told you it works better?
It was a gimmick for long-pipes in Pentium 4s.
Most of the current processors have short-pipes and hardly gain from
Hyper-threading.

On average, this improves performance by 11%-14% when running multiple
programs.
If you're running a single program, it's probably hurting performance.
Programs that are memory or cache intensive also reduce performance under
hyper-threading.

Where does it help?
Programs specifically written for multi-threaded use of the CPU. Rendering,
multi-media, etc.


<> wrote in message
news...
On Sun, 5 Aug 2007 10:54:01 -0700, HectorziN
<> wrote:

>I have Vista Ultimate installed and I installed it having HT activate.
>Now I am interested disabling HT, because it works better to run processes
>not prepared for multitasking.

who in the world told you that ? And where are you getting these antique
programs that will actually install on a hyper threading machine that won't
work ?

>If I disable HT from BIOS, then Windows Vista stops booting just when the
>progress bar (starting windows) should start.
yeah.. And you'll probably see a lot more instabilities if you continue.

>If I run in safe mode, also hangs after loading some drivers.
>The only way to get windows vista to restart again is enabling again HT.
>
>How can I disable HT and get to run Vista again?
Why ? Upgrade the software. Use that hyper threading.. Use the multi
tasking.
I think the machine's already told you it's not going to work with no HT.
--
more pix @ http://members.toast.net/cbminfo/index.html

<snip>

>who in the world told you that ? And where are you getting these antique
>programs that will actually install on a hyper threading machine that won't
>work ?

I had a program that wouldn't work in XP if HT was enabled in the BIOS. It
was a "new" program at the time and the mfg's website recommended disabling
HT to get the program to work. It was the sw for a TV card. Just a couple of
years old at this point. So I don't think it's an "...antique programs..."
issue.

<snip>

Lang

"HectorziN" <> wrote in message
news:9269DAB2-6F08-4F43-9164-...
>I have Vista Ultimate installed and I installed it having HT activate.
> Now I am interested disabling HT, because it works better to run processes
> not prepared for multitasking.
> If I disable HT from BIOS, then Windows Vista stops booting just when the
> progress bar (starting windows) should start.
> If I run in safe mode, also hangs after loading some drivers.
> The only way to get windows vista to restart again is enabling again HT.
>
> How can I disable HT and get to run Vista again?
>
> thanks
>

<snip>

I don't know for sure... I'll take a SWAG, though...

If I were in your shoes, I'd try disabling HT in the BIOS, boot from the
Vista DVD, and run a repair. I can only assume that Vista's HAL has some tie
to whether HT is enabled or disabled when installed. Again, that just a
SWAG, with no data to back it up. (And it seems to run against what I know
about XP, but Vista ain't XP... so...)

Before you try that, you might try a google on "vista ht disable" or
something like that...

Good luck!

Lang

Hello again.
I am totally interested disabling hyperthreading. I will explain why.
When I bought my computer, I had HT deactivated. I am a developer, and I
have developed an optimization program. This program uses an iterative
algorithm to optimize and each iteration depends from the previous one. This
avoid paralelizing. Having HT disable i got about 2 millions iterations per
minute.
Then, one day, I found that my soft start going about 1.3 iterations and the
CPU used was only 50%. I haven't found de reason... Now I know that it is
because HT was activated later (one day modifing my BIOS configuration, I
activated it without knowing exactly what is HT). conclusion: activating HT
converts my 3.6 GHz processor in 2x2.0 GHz processors (more or less). I
preffer having one 3.6 processors.This is my explanation, because I don't
want having HT activate.
Then my problem isn't knowing if I must having it activate or not. I know
that I want it deactivated.

when activating doesn't boot, because Vista has been installed having it on.
I don't know why vista don't boot and then, after booting, install required
components to arrange the SO...
I have boot from DVD and I tried to reparir, but the result is that it don't
find problems in the installation of Vista. then don't repair anything. I
also tried to reinstall Vista with the option of update my current version of
vista (to maintain all my installed programs) and after this, I had a blue
screen when booting. THANKS TO Microsoft to add de ROLLBACK. I recover with
this option my old installation.
I have search in google, but no solution found.

Thanks!!!

"Lang Murphy" wrote:

> "HectorziN" <> wrote in message
> news:9269DAB2-6F08-4F43-9164-...
> >I have Vista Ultimate installed and I installed it having HT activate.
> > Now I am interested disabling HT, because it works better to run processes
> > not prepared for multitasking.
> > If I disable HT from BIOS, then Windows Vista stops booting just when the
> > progress bar (starting windows) should start.
> > If I run in safe mode, also hangs after loading some drivers.
> > The only way to get windows vista to restart again is enabling again HT.
> >
> > How can I disable HT and get to run Vista again?
> >
> > thanks
> >
>
> <snip>
>
> I don't know for sure... I'll take a SWAG, though...
>
> If I were in your shoes, I'd try disabling HT in the BIOS, boot from the
> Vista DVD, and run a repair. I can only assume that Vista's HAL has some tie
> to whether HT is enabled or disabled when installed. Again, that just a
> SWAG, with no data to back it up. (And it seems to run against what I know
> about XP, but Vista ain't XP... so...)
>
> Before you try that, you might try a google on "vista ht disable" or
> something like that...
>
> Good luck!
>
> Lang
>
>

On Mon, 6 Aug 2007 00:04:41 -0400, "Lang Murphy" <> wrote:

><snip>
>
>>who in the world told you that ? And where are you getting these antique
>>programs that will actually install on a hyper threading machine that won't
>>work ?
>
>I had a program that wouldn't work in XP if HT was enabled in the BIOS. It
>was a "new" program at the time and the mfg's website recommended disabling
>HT to get the program to work. It was the sw for a TV card. Just a couple of
>years old at this point. So I don't think it's an "...antique programs..."
>issue.

But in this case it's definitely a tech issue. I don't know what a SW is.IOW the tech didn't know enough about HT or machines in general it seems.
You've already proven you can't run with HT off.

I had a 3.2 ghz. HT. ran great. had the ATI 9800 in it. I'd look for other solutions besides disabling the machines normal operation.
--
more pix @ http://members.toast.net/cbminfo/index.html

"HectorziN" <> wrote in message
news:7569A427-069B-4258-9E90-...
> Hello again.
> I am totally interested disabling hyperthreading. I will explain why.
> When I bought my computer, I had HT deactivated. I am a developer, and I
> have developed an optimization program. This program uses an iterative
> algorithm to optimize and each iteration depends from the previous one.
> This
> avoid paralelizing. Having HT disable i got about 2 millions iterations
> per
> minute.
> Then, one day, I found that my soft start going about 1.3 iterations and
> the
> CPU used was only 50%. I haven't found de reason... Now I know that it is
> because HT was activated later (one day modifing my BIOS configuration, I
> activated it without knowing exactly what is HT). conclusion: activating
> HT
> converts my 3.6 GHz processor in 2x2.0 GHz processors (more or less). I
> preffer having one 3.6 processors.This is my explanation, because I don't
> want having HT activate.
> Then my problem isn't knowing if I must having it activate or not. I know
> that I want it deactivated.
>
> when activating doesn't boot, because Vista has been installed having it
> on.
> I don't know why vista don't boot and then, after booting, install
> required
> components to arrange the SO...
> I have boot from DVD and I tried to reparir, but the result is that it
> don't
> find problems in the installation of Vista. then don't repair anything. I
> also tried to reinstall Vista with the option of update my current version
> of
> vista (to maintain all my installed programs) and after this, I had a blue
> screen when booting. THANKS TO Microsoft to add de ROLLBACK. I recover
> with
> this option my old installation.
> I have search in google, but no solution found.
>
> Thanks!!!

Well... then... if I were in your shoes, I'd back up all my data, disable HT
in the BIOS, and do a clean install of Vista. Yeah, that sucks cause you'd
have to reinstall all your apps... and you might still get a BSOD on boot.

Do you have the latest BIOS for your mobo installed? And... just curious, is
it your intention that this application you're developing only be run on
non-HT CPU's?

Lang