Guest Win10 is configured for 16 processors, but the VM sees just 2 of them.

[Ihor_Bobak]

I have a guest VM  with Windows 10 which was previously migrated from VirtualBox.

I have 16 processors configured (see the screenshot), however, when I run the VM and look in the task manager, I see that VM has just 2 processors (but not 16).

Does anyone have an idea why this might happen? Why doesn't the guest machine see all assigned processors?

Vmx file is also attached.   Thanks in advance.

Version of VMWare Workstation Pro: 16.1.2 build-17966106, host machine with Ubuntu 20.04, guest OS:  Windows 10 Pro build 19043

 

[bluefirestorm]

From the screenshot, you need to reverse the numbers, set the processors to 1 and cores to 16.

The number of processors is the number of (virtual) sockets. Windows 10 Professional is limited to 2 sockets; Windows 10 Home is limited to 1, Windows 10 Pro Workstations is limited to 4.

[Ihor_Bobak]

After I did this, I am getting blue screen of death.  Vmware restarts the VM multiple times, and multiple times I am getting this same screen....

[bluefirestorm]

Lately, there seems to be occurring more often also to me with VMware Workstation Pro 15.5.7 on Ubuntu host and Fusion 11.5.7 on macOS Catalina. Whenever I set to 4 or more vCPUs, the Windows 10 VM can crash with SYSTEM_THREAD_EXCEPTION_NOT_HANDLED during power up.

I cannot tell you the exact trick to get it to work as I am not exactly sure. It seems to be a timing issue and/or where the mouse pointer is when the VM is starting up. For a MacBook Pro host, I cannot seem to get around it if the host is running on battery power.

Try to get the VM to boot first by reducing the number of vCPUs to <4. So try a virtual socket/virtual cores of either 2/1, 1/2, or 1/3.

There should be no performance difference with virtual socket count of 1 or 2. It only matters on the licensing limitations in this case of Windows 10 Professional.

[Ihor_Bobak]

If I set sockets = 1 and cores = 4, it still works.   If I set sockets = 1 and cores = 8, it doesn't work.

I don't believe that this is a limitation of Win10Pro because on VirtualBox this VM was running on 16 cores and everything was pretty fine.

Just to check:  I installed a fresh copy of Win10, and set 16 cores, and it works.

Something is wrong with particularly THAT VM which was imported from VirtualBox. I am in despair....

[bluefirestorm]

As I said, I don't know what causes it. You're the one of the few people I encountered in this forum who also faces a similar problem but you don't have to despair.

First time I encountered this problem was when trying to upgrade from Windows 10 1909 to 20H1. The BSOD shows up when during the reboot phase of the upgrade when vCPU was 4.

Anyway, the initial workaround was to add the hypervisor services in the VM (thus enable "Virtualize Intel VT-x/EPT or AMV-V/RVI" in the Processors settings).

Eventually, with subsequent updates, it kept occurring more often during power up despite this Hyper-V workaround.

So I have reinstalled the VM OS, also changed from variable size virtual disk to preallocated virtual disk.

For the Ubuntu host with Workstation Pro 15.5.7, what I did was  a fresh install of a Windows 10 VM from 20H2 USB created from Windows 10 Media Creator.
For the macOS host with Fusion 11.5.7, what I did was fresh install of Windows 10 20H2 but choose repair to restore from backup all the apps in the previous VM.

The frequency of the BSOD is far less than the one on VMware Fusion but it still can happen. I don't know exactly what the cause is, but the way I approach it when I power up the Ubuntu host, I would not open any other applications (including Firefox browser). Then I open VMware Workstation after waiting a while (maybe 30 seconds to 1 minute). I have dual monitors on this Ubuntu what I do is I put the mouse pointer on the second screen.

So you could try adding the Hyper-V services into the Windows 10 VM and see if it allows you to have >=8 vCPUs.
Or you could try creating another VM fresh from Windows 10 20H2 or 21H1 ISO/USB.