Explain the difference between the two articles(1 says XP home can tak

[Deltaxp]

Here are the two articles

http://support.microsoft.com/kb/896256/en-us

And

http://www.techbuilder.org/recipes/169500107

One talks about How XP can support dual core and mentions "(ACPI) processor performance states"

And the other says XP home will not take full advantage due to Symmetric Multi-Processing (SMP)

Of coarse XP home will run on Core duo but my understanding is "it is not capable of taking full advantage of both cores."

Can somebody look at the two article and explain the differences between them. and most important why or why not XP home can take full advantage of dual core

Thank you

Jo

Edited January 16, 2007 by Deltaxp

[cluberti]

The issue is that power states, until dual-core (and multi-core) processors, used to be able to be handled and addressed per processor. Now, with more than one core on a processor die, the power state and performance state functionality of a processor can actually be two physical cores on one proessor, and the kernel needs to understand that one physical processor may expose 2 *real* processors and those are not virtual processor cores. Again, with hyperthreading, this wasn't a problem, as the exposed processors were virtual and both were actually just one processor. With actual cores, this becomes a power and state switching problem that was addressed in the hotfix kernel, to a point. However, Vista and Longhorn's kernels "understand" multi-core processors, whereas XP and 2003's kernels only "sort-of" understand it, and have been modified to work around their shortcomings. They'll use both processors for running code properly, yes, but other power-specific and performance-specific features internal to the processors may not be supported 100%.

[Deltaxp]

Thank you,

Jo