proxmox - server 2019 - not all cpu cores are used during compression

[sigmarb]

Hi folks,

I'm running a windows server 2019 and doing some benchmark to compress several mp4-video files into a zip-file with windows build in "compress" tool.
Monitoring the cpu usage shows that only a few cores are used and it's pretty slow.

Is this some kind of limitation due to virtualization?

Server has

dual CPU AMD EPYC 7301 16-Core Processor

My windows laptop uses all cores during the compression task and is 10 times faster.

configuration attached from the server 2019 VM:

balloon: 0
bootdisk: scsi0
cores: 8
ide2: none,media=cdrom
ide3: none,media=cdrom
memory: 64000
name: server2019
net0: virtio=F2:15:59:D7:32:D1,bridge=vmbr0,tag=200
numa: 1
ostype: win10
scsi0: rbd_ssd:vm-114-disk-0,discard=on,size=400G
scsihw: virtio-scsi-pci
smbios1: uuid=d7c36b04-664e-40a5-9968-1d81b4f1d9d9
sockets: 2
vmgenid: 4e3e564e-634a-44ef-94cb-e7d2e04f9143

my laptop shows:

 

[Dunuin]

Your VM is using the default "kvm64" CPU. That one might be a good choice for a non-homogenious cluster, because it should work with most hardware architectures, because it only uses a striped down set of instructions. So your VM basically can't make use of all features your CPU is offering, so it will be slower.
You could set the CPU type of that VM to "host" and see if the performance gets better (it usually does).

 

[sigmarb]

Your VM is using the default "kvm64" CPU. That one might be a good choice for a non-homogenious cluster, because it should work with most hardware architectures, because it only uses a striped down set of instructions. So your VM basically can't make use of all features your CPU is offering, so it will be slower.
You could set the CPU type of that VM to "host" and see if the performance gets better (it usually does).

Thank you. I will test this. I was aware that default lacks some native cpu flags, but i could not find a reason why it should not scale on all cores. Will test and report back.