Win10 with GPU passthrough sluggish performance

Mr. A

Member
May 24, 2021
5
1
8
Sussex, GB
G'day all,

DELL R520, H710 RAID6, WD reds. 2 x Xeon 2450 v2 55GB RAM, Proxmox user for about 6 years. iSCIS volume of a NAS for vmbackups.

I've been using this box quite happily for a multitude of linux VMs, all quite happy for a year or so.

Even the windows VMs have been ok.

So took the plunge and added a AMD RG220 Graphics (PCoIP version) , and passed it through to a Win10 VM,
(Client is a PCoIP TERA2321 thin client, which has worked very well over the years, keeping noisy tin out of the living room. )
One thing I've had to do is blacklist the AMD's onboard snd_hda_intel, as that just hang prox on boot. (debian bug it seems...)

Win10 grumbled and BSOD at first, but eventually settled down and is now stable. ( First attempt, lost the mouse/keyboard after a windows update so had to start again. )

but performance is a bit... lacking... compared with non-pass through VMs I intailly only gave it 8 cores, but upped it to 16. VM has 16GB of RAM (non baloon)

Inside the VM, windows reports CPU usage 20% ? - mem usage is 40%

but what I do see in task manger is System interrupts wiht high usage... this is born out when using sound with all sorts of pops and crackles. (using USB over IP to the sound bar.)


here's the dirt,
Promxox VE 6.2-2

Code:
agent: 1
balloon: 0
bios: ovmf
boot: dcn
bootdisk: sata0
cores: 16
cpu: host
efidisk0: local-pvedata0:1015/vm-1015-disk-1.qcow2,size=128K
hostpci0: 43:00,pcie=1,x-vga=1
hostpci1: 44:00,pcie=1
machine: q35
memory: 16384
name: 1015-Win10x
net0: e1000=96:A6:E3:35:8A:EC,bridge=vmbr0,firewall=1
numa: 1
ostype: win10
sata0: local-pvedata0:1015/vm-1015-disk-0.qcow2,cache=writethrough,size=450G
sata2: local:iso/virtio-win-0.1.190.iso,media=cdrom,size=489986K
scsihw: virtio-scsi-pci
smbios1: uuid=52917f26-bd8d-4363-98cd-61a726d7a3bf
sockets: 1
vmgenid: 5d9c41e7-e21d-472a-8670-1f917ffd0911

anything look untoward ?
would dumping the AMD's bios help ? (rombar etc...?)
Any other thoughts ?


Many thanks
Mark
 
mhmm.. config looks mostly ok, i'd change the nic from e1000 to virtio and the disks from sata to scsi
this could reduce the cpu overhead qemu has to do since virtio-nic and virtio-scsi do not really emulate devices
 

About

The Proxmox community has been around for many years and offers help and support for Proxmox VE, Proxmox Backup Server, and Proxmox Mail Gateway.
We think our community is one of the best thanks to people like you!

Get your subscription!

The Proxmox team works very hard to make sure you are running the best software and getting stable updates and security enhancements, as well as quick enterprise support. Tens of thousands of happy customers have a Proxmox subscription. Get yours easily in our online shop.

Buy now!