Brilliant question.
I found this with Vista64 only recently.
Never have it with XP64, and single core apps get given usage of one core.
It really brought it to light for me, as I have been running 4 clients of Folding At Home, each client takes up 100% of its core, or 25% or the total CPU, and as you know, 25% x 4 Cores = 100% and this was absolutely great, but when I looked aty the Task Managers CPU useage, it was all scrappy and all over the place??
On further testing, I knocked it down to only one client and sure enough, it was taking its allotted 25%, but this was spread out over the 4 cores?
Sure enough, I can force this to only one core and indeed I can do this for all 4 clients, giving each client access to only one core, but why?
Here is the real bugger though...
Folding At home is now supposed to know and use Multicore CPUs, and yet, why does it still only actually use the power of one core, but spread it over the 4? - Why does it not try to use the power of all 4 cores?
So, I too am curious as to how this is so?
Like I said, I never had it on XP64, only Vista64, so if anyone can verify this, plus also since dropping down to only one client of FAH, Vista is now running rock solid, so where XP64 is capable of running 4 clients, Vista has issues. Can anyone else verify that?
