Slow Windows 11 Performance

[Ashkaan4]

Hi there,


I've been searching for a week and can't find the answer. Why is my Windows 11 VM so slow??

I'm simply testing the UI via RDP between several machines (2x VMs and 2x bare metal computers). The 2x bare metal computers are snappy and HIGHLY responsive. The 2x VMs struggle just moving windows around.

I've tried building new VMs and installing windows fresh with latest virtio drivers with the exact results. I've read other posts here and people pointing to a lack of GPU, but as I understand it, RDP doesn't use GPU. Plus, I've tried all of the virtual GPU options.

What is it???

agent: 1
balloon: 0
bios: ovmf
boot: order=virtio0
cores: 32
cpu: x86-64-v2-AES
efidisk0: local-zfs:vm-500-disk-0,efitype=4m,pre-enrolled-keys=1,size=1M
machine: pc-q35-9.0
memory: 32768
meta: creation-qemu=8.0.2,ctime=1692374606
name: windows
net0: virtio=6a:f1:4f:7e:0f:72,bridge=vmbr0,firewall=1,mtu=9000
numa: 1
onboot: 1
ostype: win11
protection: 1
scsihw: virtio-scsi-single
smbios1: uuid=5474fbd5-289f-468b-940f-0917669f5ad0
sockets: 1
tablet: 1
tpmstate0: local-zfs:vm-500-disk-1,size=4M,version=v2.0
vga: virtio,memory=256
virtio0: local-zfs:vm-500-disk-2,iothread=1,size=128G
vmgenid: 437d21e6-6cd4-4e5c-a8cf-561a8d240781

 

[alexskysilk]

1. you specified 32 cores. Do you have 32 cores? are they amd? try to keep to 8 or less to avoid numa traversal issues. Generally speaking, if your vm needs 32 cores you're probably better off installing it directly on the metal.
2. whats your zpool look like (disks type/organization.) My guess is this is your issue, but lets continue.
3. you set mtu 9000 for your nic. why? are your switches explicitly set to jumbo frames?
4. setting your cpu to host may help.

 

[Ashkaan4]

Thanks for the reply!

1. Yes, the machine has 72x cores, but I did try 8x just to test NUMA issues and it's exactly the same.
2. It's a RAID0 ZFS with 2x fast SSDs
3. They are set to 9000. I tried 1500 with the same result.
4. Makes my VMs crash (rarely), so I stopped using host.

 

[alexskysilk]

I reread your initial post, and maybe I was looking at the wrong thing.

change your vga to default. does it change anything?

 

[Ashkaan4]

Nothing. I started with Default and have tried each of the settings there.

I also moved the hdd to a 36x HDD ZFS System on 10G with excellent IOPS and low latency with the identical result.

It's like the VM is underwater. Even Terminal takes like 8 seconds to open.

 

[alexskysilk]

search the forums. this is probably qemu/kernel version specific.

 

[Ashkaan4]

As I mentioned above, I have been searching for weeks and haven't found any solutions yet.

It's been like this since Proxmox 7.0 so I don't think it's qemu/kernel version specific.