My Windows VM is very slow

[R3tr0]

Hi,
My Windows VM has 24 cores and 32GB of ram. However, when i am moving the mouse around in the VM it is often very slow and i cannot click on things because it is very laggy. Is there any way to speed it up?

 

[Dunuin]

First you should find out what the problem is. For example if your VM is actually fast, but just the remote desktop connection is bad, so it looks slow/laggy to you. In case you got GPU passed though you could connect a display directly to that GPU and see if it is still slow.
Then I would check network, disk, RAM, CPU, GPU benchmarks inside the VM to see if there is a botleneck, in case it is not the remote desktop connection.
Also make sure "KVM hardware acceleration" is enabled in the VMs options, that you don't run nested virtualization, that the CPU type is set to host and that you use virtio SCSI as the disk controller and virtio as the NIC.
And keep in mind that without a passed through GPU all graphics will have to be rendered in software by the CPU which is super slow and even a 720p youtube playback might stutter.

 

[R3tr0]

First you should find out what the problem is. For example if your VM is actually fast, but just the remote desktop connection is bad, so it looks slow/laggy to you. In case you got GPU passed though you could connect a display directly to that GPU and see if it is still slow.
Then I would check network, disk, RAM, CPU, GPU benchmarks inside the VM to see if there is a botleneck, in case it is not the remote desktop connection.
Also make sure "KVM hardware acceleration" is enabled in the VMs options, that you don't run nested virtualization, that the CPU type is set to host and that you use virtio SCSI as the disk controller and virtio as the NIC.
And keep in mind that without a passed through GPU all graphics will have to be rendered in software by the CPU which is super slow and even a 720p youtube playback might stutter.

Thanks man, Ive set the CPU to host and i notice an improvement instantly.

 

[masonh]

are there any other sloutionss

 

[3degreesright]

I too have the CPU set to "Host" and experience a very slow Windows 10 VM on Proxmox 8.1. Proxmox 8.2 would NOT install on my Dell R610 dues to some undocumented bug.

I am using nested virtulization, as this is a requirement. I am also using the following settings:

• benchmarks look good on CPU = 10-25%, RAM = 4/16 GB
• No passthrough GPU, but graphics are not my concern here
• local Gbit network, not an RDP or bandwidth issue
• SCSI Controller, but the disk is on (ide0)
  • When i try a SCSI disk for the Windows host I'm not sure which driver to load, so I left default ied0
• VirtIO = SCSI Controller, Network card,
• virtio-win-0.1.262 mounted and installed

Any ideas are greatly appreciated!!
Thanks!!

 

[aghadjip]

i too have very poor perf on cpu=host. have a threadripper and need to use cpu=epyc or similar, but then i lose virtualization.