Hyperthreading hurts 5.3?

David Kelly dkelly at HiWAAY.net
Tue Jan 11 19:50:21 PST 2005

On Jan 11, 2005, at 9:18 PM, Chuck Swiger wrote:

> David Kelly wrote:
>>> (disabling HT will apparently mean I have to reinstall XP on the 
>>> other
>>> drive.
>> What does XP have to do with it? IIRC on Dell its F2 during the 
>> power-on diagnostics to reach the built-in BIOS config. That is where 
>> HT is to be disabled.
> If you install and configure many flavors of Windows on a SMP system, 
> that installation will not work if you move that image to a uni-proc 
> system by swapping disks or otherwise removing CPU's (ie, by turning 
> off HT'ing).  I last saw this with a Win2K system, which immediately 
> blue-screened with an "invalid SMP HAL" error very early in the boot.

OK, that makes Microsoft-logic sense. Had it in my head that he was 
saying the need to reinstall XP on a HD was to have a utility to toggle 
the HT bit in BIOS.

OTOH I've heard of others toggling the HT bit but don't remember 
anything about having to reinstall XP. Last I had a similar dealing was 
with NT4SP4, possibly with the "upgrade" to NT4SP6 when I somehow lost 
one of my 450 MHz CPU's. Found instructions on how to revive the 2nd 
CPU but left it alone as it was far better for the company server to be 
running on one CPU than the risk of damaging the install worse than it 
already was.

Last time I had to reinstall NT4SP6 it took 3 days of patch, reboot, 
repeat, before the OS install was complete.

Decided it was time for a clean wipe installation on my laptop when 
Panther was released. Believe it took 15 minutes. About the same for a 
text-only installation of FreeBSD on my Dell Optiplex.

David Kelly N4HHE, dkelly at HiWAAY.net
Whom computers would destroy, they must first drive mad.

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