Massive performance issue with Parallels and macOS Mojave

Hi,

This is a very difficult issue to describe, but it is so severe that I have been considering moving to a RDS based solution for a while now. Here is the problem - I have been using Parallels since v2 or something with great success. However, since v13 I think, on Mojave and the version before it, on my iMac Pro I find that randomly (can be daily or weekly) either after booting up Windows 10 Pro in the VM (macOS is the host), or just randomly without me doing much other than say loading an application in Windows, (I am running in Window mode), the host OS will lock up. More specifically:

1. I will see the spinning beachball icon for almost everything I do - clicking an app inside the VM, trying to work in a mac app - the spinning beachball will show up, and I will have an unresponsive UI for any time between 5 seconds to sometimes an hour where I can not do anything. Switching desktops on macOS would sometimes pause halfway through the sliding animation until it resumes a couple of minutes later. I can usually click several mac app windows and they will be brought to the foreground, but the app itself will usually be unresponsive for several seconds to several minutes, then it is as if the OS can give it perhaps m1 - 5 seconds of processing time only to lock up again.
2. Sometimes during these lockups the system clock will even freeze, and then catch up seconds or minutes or sometimes, an hour later.
3. During this time prl_disp_service is usually consuming 60% CPU and most of that is kernel time.
4. Trying to shut down the VM and parallels and relaunching is usually met with 1 - 3 hours of waiting for it to shut down. Once it is completely gone (closed), the system immediately becomes responsive again and everything is super fluid.
5. If I do not launch parallels after a reboot, the system NEVER exhibits this behaviour. I have worked for a week with no issues as long as I never launch parallels.
6. Launching parallels and the VM will have a 50% probability of locking the system up like this. Sometimes after 10 - 20 minutes of this intermittent lockup it will stop on its own (like right now) and I can work further - both in the host and guest OS.
7. I do not have a resource limit issue - I have 128GB of RAM (16GB is assigned to the VM), 2TB of SSD (VM is about 160GB), and I have one secondary monitor.
8. Everything is fully patched - Windows, Parallels, macOS etc.
9. I cannot pinpoint a specific action or timing or combination of events that trigger this behaviour - it seems random to me.
10. It has been ongoing for about a year now.

Any ideas?

 

Try switching from the Parallels Hypervisor to the Apple Hypervisor - that fixed Windows 10 VM issues for me.

 

I should have mentioned but I did try this (twice) and it behaved the same.