Windows 10 Not Using Both CPU's

HI all! I've searched in the forum and can't find anything specific to this so I'm afraid it's a new thread.

I have a Xeon system that uses two CPU's (X5450). When using Windows 8.1 both CPUs showed up on my System Properties and when I also looked at Task Manager.

Now since upgrading to Win 10 it's showing that all CPU's are installed (pic 1) and detected but I don't think it's utilizing both of them (pic 2 and 3).

Any fix for this? If not I'm going to roll back to Win 8.1 when both were used.

Help is greatly appreciated :)

I believe Windows 10 Home is limited to 1 physical CPU. CPUs over the limit will be ignored. Home versions of Windows going back to XP have always had this limit. There is no workaround.

You will need Windows 10 Pro to use all CPUs.

Note that this is a limit on the physical CPUs, not cores. Limits on cores are well above what any current CPU can provide.

I'm pretty sure that post #2 is correct, although I haven't been able to find a Microsoft link to that.

Another way of putting it: physical CPUs = sockets.

I wonder why the OP didn't upgrade to Win 10 Pro. To have run dual sockets in 8.1, the machine must have had 8.1 Pro installed.

bobkn said:

I'm pretty sure that post #2 is correct, although I haven't been able to find a Microsoft link to that.

Another way of putting it: physical CPUs = sockets.

I wonder why the OP didn't upgrade to Win 10 Pro. To have run dual sockets in 8.1, the machine must have had 8.1 Pro installed.

I was thinking about something else when I wrote the post. I had Win7 Ultimate installed and that showed all my sockets. I have since re-installed everything (since my start button refused to work) and put Pro on it. Now all RAM and sockets are being used.

Thanks all!

Home versions have always been limited to 1 physical CPU.

Hi all. I know this waking up an old thread but I installed W7 Ultimate and it upgraded to W10 Pro. All processors are now being used. Thanks for your help!