Carl Kaufmann said:
XP doesn't care about cores/socket, only sockets. XP Pro will use
both, Home will use only one.
If what you mean is that XP will only see 1 core
per physical socket, that is incorrect.
I am running 2 dual-core Xeons on an ASUS
PC-DL and Task Manager shows 4 CPU Usage
graphs. XP "thinks" it has 4 logical processors.
As far as "using" all your cores, the OS will, but
very few applications know how to do this (some
imaging software, some video transcoding software)
and will continue to poke along using only 1 core.
But multi-cores will allow you to run lots of apps
simultaneously at full speed and will offload OS chores to other
cores.