Slow Windows 10 VM

[Ashdev]

Hi,

I know it's a recurring topic but I've read everything I could find and I have not found a solution that worked for me.

I have a Windows 10 VM in my proxmox server (Actually the only VM for this server for now until I figure what's the issue).
I wanted to use this VM as a workstation / gaming cloud.
It has GPU passthrough using vGPU and I'm currently giving this VM all my CPU cores.

Overall windows is running correctly but always seems slow and laggy.
When I look at the CPU and GPU usage it's low, same for the memory.
I tried with and without ballooning, changing the disk cache policy, nothing really made a huge difference.

I am using Parsec to connect to the VM, I use Parsec on other machines so I discarded it as a potential issue but could be the issue.

My server summary:

CPU(s)                 48 x Intel(R) Xeon(R) CPU E5-2695 v2 @ 2.40GHz (2 Sockets)
RAM                    192 GB
Kernel Version         Linux 5.15.35-3-pve #1 SMP PVE 5.15.35-6 (Fri, 17 Jun 2022 13:42:35 +0200)
PVE Manager Version    pve-manager/7.2-5/12f1e639

This is the config I'm using for the VM:

agent: 1
args: -uuid 00000000-0000-0000-0000-000000002001
balloon: 0
bios: ovmf
boot: order=scsi0;net0;ide0
cores: 12
cpu: host
efidisk0: compute:vm-2001-disk-0,efitype=4m,pre-enrolled-keys=1,size=4M
hostpci0: 0000:04:00.0,mdev=nvidia-22
machine: pc-q35-6.2
memory: 65536
meta: creation-qemu=6.2.0,ctime=1656425796
name: Workstation
net0: virtio=7e:40:10:df:ed:62,bridge=vmbr0,firewall=1
numa: 0
ostype: win10
scsi0: compute:vm-2001-disk-1,cache=writeback,size=512G
scsi1: data2:vm-2001-disk-0,cache=writeback,size=500G
scsihw: virtio-scsi-pci
smbios1: uuid=460baf4b-f623-434a-9c9c-97b3d3398ff2
sockets: 2
tpmstate0: compute:vm-2001-disk-2,size=4M,version=v2.0
vmgenid: 082fc168-c2bf-48a6-8ab6-31a50fe5125a

Thank you.

 

[smecio]

I usually make it simple by setting the number of sockets of the VM to 1. Some more questions that may help:

1. Have you had VirtIO drivers installed on the VM?
2. What are the configurations of the storages named compute and data2?
3. have you had the proper NVidia drivers installed on the VM?

 

[Dunuin]

Config all looks fine. Don't know what else could be optimized except for "virtio SCSI single" instead of "virtio SCSI" and enabling NUMA.

Good idea would be to run some CPU, RAM and DISK benchmarks inside and outside the VM to see if there is a bottleneck somewhere.

Also keep in mind that you got alot of cores but the CPUs aren`t fast in single threaded performance. So great as a workstation or hypervisor but not good for gaming.

 

[Ashdev]

I usually make it simple by setting the number of sockets of the VM to 1. Some more questions that may help:

1. Have you had VirtIO drivers installed on the VM?
2. What are the configurations of the storages named compute and data2?
3. have you had the proper NVidia drivers installed on the VM?

I did install the VirtIO drivers.
Both storage are LVM-Thin using a Raid 1 setup in PERC on the server (R720)
I have intalled the Nvidia GRID Driver from nvid.nvidia.com on the machine and the corresponding driver in the VM

Config all looks fine. Don't know what else could be optimized except for "virtio SCSI single" instead of "virtio SCSI" and enabling NUMA.

Good idea would be to run some CPU, RAM and DISK benchmarks inside and outside the VM to see if there is a bottleneck somewhere.

Also keep in mind that you got alot of cores but the CPUs aren`t fast in single threaded performance. So great as a workstation or hypervisor but not good for gaming.

Thanks for the advices, I'll look into that and try to enable NUMA

 

[Ashdev]

I'm not sure it changed a lot but I enabled NUMA and swiitch to virtio SCSI single.

It feels a bit more fluid in windows but the games are still slow even though it's not using all the CPU/RAM/GPU.

I did a benchmark before and after and it's the same result.

 

[Dunuin]

Did you look at the task manager while the games are running? Usually games only make use of a few CPU cores. If a game can only make use of 1-4 cores it won't help if the VM got 12 cores. Then 1-4 cores are at 90+% load while the other ones are idling. For games and other similar workloads that benefit from single-threaded performance you really want a CPU with less but faster cores.

 

[Neobin]

Overall windows is running correctly but always seems slow and laggy.

Did you already test this exact hardware with a bare-metal Windows 10 installation and the same workloads/tests?
How do they do in comparison?

Do you have (or can you get) several benchmark numbers comparing bare-metal Windows 10 vs. virtualized Windows 10 on that exact hardware?

Edit to explain my questions above:
Do you already know for sure (self-tested beforehand), that your given (9 year old [1] with really low single core performance) hardware is up to your tasks and your performance expectations with an bare-metal Windows 10 installation?

[1] https://ark.intel.com/content/www/u...n-processor-e52695-v2-30m-cache-2-40-ghz.html