The ACPI Multiprocessor PC HAL will run fine on machines that would normally
run the ACPI Uniprocess PC HAL. There is a little extra overhead in doing
this (a couple of percentage points) but it works fine.

The ACPI Uniprocessor PC HAL or ACPI Multiprocessor HAL will most likely
crash on a machine that normally runs the "Advanced Configuration Power
Interface PC" HAL.

-Michael Niehaus
Systems Design Engineer
mniehaus@microsoft.com
This posting is provided "AS IS" with no warranties, and confers no rights.

"Bjorn" <Bjorn@discussions.microsoft.com> wrote in message
news:668DA4DE-4527-47F8-BAE8-459B678C914E@microsoft.com...
> How about running a multiprocessor HAL on a uniprocessor computer...?
> I have a master image here, configured with a multiprocessor HAL, that
> runs
> just fine on my uniprocessor computers too. Are there any issues I should
> be
> concerned about?
>
> "Michael Niehaus [MS]" wrote:
>
>> Apart from the "unsupported" part of this (as you've seen, it works fine
>> in
>> most cases), there is another downside: If you use the ACPI HAL, you
>> won't
>> get any benefits from Intel's hyperthreaded processors. You also won't
>> be
>> able to take advantage of dual-core processors. Windows will only see
>> one.
>>
>> -Michael Niehaus
>> Systems Design Engineer
>> mniehaus@microsoft.com
>> This posting is provided "AS IS" with no warranties, and confers no
>> rights.
>>
>>
>> "Adam Leinss" <aleinss@techie.com> wrote in message
>> news:Xns972BCAFF412E6aleinsstechie@toughguy.net...
>> > "SameOld" <andrew_paiti@hotmail.com> wrote in
>> > news:1134517060.781159@huey.topnz.ac.nz:
>> >
>> >> Well two images is better than 18!
>> >>
>> >> I have read on a few blogs that i should build my master on a MP
>> >> HAL so as to avoid any issues with the UP PC's being incorrectly
>> >> given a MP HAL which will work but with a degraded performance.
>> >> Your thoughts on this?
>> >
>> > Check out http://aleinsstechtips.blogspot.com/2005_07_01
>> > _aleinsstechtips_archive.html.
>> >
>> > Though not supported by Microsoft, by using the ACPI HAL solely my
>> > master image supported 3 laptops and 4 PCs.
>> >
>> > Adam
>>
>>
>>