vmware esxi – Windows 2016 Server VM – dialogs in various apps are displayed after tens of seconds when CPU usage is around 20%-30%

This issue baffles me.

I’ve been given a Windows 2016 Server VM to do development on. The specs for the VM are:

Hypervisor: VMware ESXi, 6.5.0, 13004031
Model: ProLiant BL460c Gen8
Processor Type: Intel (R) Xeon(R) CPU E5-2560 0 @2.00GHz

Specs from the Windows system information:
OS Name Microsoft Windows Server 2016 Standard
Version 10.0.14393 Build 14393
Other OS Description    Not Available
OS Manufacturer Microsoft Corporation
System Manufacturer VMware, Inc.
System Model    VMware Virtual Platform
System Type x64-based PC
System SKU  
Processor   Intel(R) Xeon(R) CPU E5-2650 0 @ 2.00GHz, 2000 Mhz, 1 Core(s), 1 Logical Processor(s)
Processor   Intel(R) Xeon(R) CPU E5-2650 0 @ 2.00GHz, 2000 Mhz, 1 Core(s), 1 Logical Processor(s)
Processor   Intel(R) Xeon(R) CPU E5-2650 0 @ 2.00GHz, 2000 Mhz, 1 Core(s), 1 Logical Processor(s)
Processor   Intel(R) Xeon(R) CPU E5-2650 0 @ 2.00GHz, 2000 Mhz, 1 Core(s), 1 Logical Processor(s)
Processor   Intel(R) Xeon(R) CPU E5-2650 0 @ 2.00GHz, 2000 Mhz, 1 Core(s), 1 Logical Processor(s)
Processor   Intel(R) Xeon(R) CPU E5-2650 0 @ 2.00GHz, 2000 Mhz, 1 Core(s), 1 Logical Processor(s)
BIOS Version/Date   Phoenix Technologies LTD 6.00, 9/19/2018
SMBIOS Version  2.4

The problem that I have is that sometimes dialogs in various applications, usually written in Delphi or Visual C++ take a long time to show up when the CPU usage is around 20%-30%.

I am using Toad Data Modeler (TDM – written in Delphi), The Journal (written in Delphi) and SAP Power Designer (PD – written probably in VC++).

When I click on a table to display the table properties, for instance, in a TDM model (this brings a dialog with lots of tabs), it can take up to 20s for the dialog to show up. In the Journal I had some weird experience where I was typing letters and they would show up one by one in slow motion. Today, I have the same issue with PD. The common pattern when I experience this slowness is a current CPU background usage of somewhere between 20 and 30%. I started to close apps and I got the CPU humming below 10% and the dialogs show up much faster.

I compared this to my Windows 10 VM running on a MBP 16″ (inside Desktop Parallels), and it is incomparable. My VM is much faster. I used the same TDM model to test, and I even have fewer cores assigned.

Any ideas? I know it’s not much information to go on, but I hope that someone with the knowledge of VMs and Windows internals has at least a theory. To me it looks like the dialogs are processed on a core that is (CPU) starved, even though the VM has been assigned 6 cores.

Thanks