I recently added a new Windows 10 VM to my UnRAID server using Q35-5.1 and virtio-win-0.1.190.1 and and I noticed when copying from the VM to the cache drive it was significantly slower than an older VM running Q35-4.2 and virtio-win-0.1.173-2. To verify, I cloned the old VM template and did a fresh Windows install and confirmed that it was much faster than using Q35-5.1 and virtio-win-0.1.190.1. I also tried i440fx-5.1 , but it was slower than Q35-5.1. Is this a known issue?

 

With Q35-5.1 / virtio-win-0.1.190-1:

 

 

 

With Q35-4.2 / virtio-win-0.1.173-2:

 

 

 

tower-diagnostics-20210129-0347.zip

Edited January 30, 20214 yr by jwoolen
formatting

Try below

 

 

Thanks Vr2lo! That fixed it. Do you know why this is necessary?

It must a bug. 😄

What’s crazy is that I changed it back to 8 and it still works.

😝😝

I set up a few more VMs recently and I found out that the culprit was the virtio-net setting under Network Model in the VM configuration. When I used virtio I didn't have any problems.