1 PC 2 Gaming VMs

[brnogu]

Hello everyone!

I'm using for some years my PC with proxmox and sharing it with my cousin with Parsec. But each time the PC is in use, my gaming VM becomes painfully slow.

This is the hardware:
CPU: 6 x Intel(R) Core(TM) i5-8400 CPU @ 2.80GHz (1 Socket)
RAM: 64GB (Motherboard max)

Cousin VM:
agent: 1
balloon: 0
bios: ovmf
boot: order=scsi0;net0;scsi2
cores: 2
cpu: host
efidisk0: Samsung_250GB_SSD:vm-105-disk-1,efitype=4m,pre-enrolled-keys=1,size=4M
hostpci0: 0000:03:00,pcie=1,x-vga=1
kvm: 1
machine: pc-q35-8.1
memory: 14336
name: CousinVM
net0: virtio=MAC,bridge=vmbr0,tag=24
numa: 1
onboot: 1
ostype: win11
scsi0: Samsung_250GB_SSD:vm-105-disk-2,cache=writeback,iothread=1,size=232G,ssd=1
scsi1: Samsung_2TB_SSD:vm-105-disk-2,cache=writeback,size=209G,ssd=1
scsihw: virtio-scsi-single
smbios1: uuid=UUID
sockets: 1
tpmstate0: Samsung_250GB_SSD:vm-105-disk-0,size=4M,version=v2.0

My VM:
agent: 1
balloon: 0
bios: ovmf
boot: order=ide2;virtio0;net0
cores: 3
cpu: host
efidisk0: Samsung_2TB_SSD:vm-104-disk-1,efitype=4m,pre-enrolled-keys=1,size=4M
hostpci0: 0000:01:00,pcie=1,x-vga=1
machine: pc-q35-8.1
memory: 17408
meta: creation-qemu=7.2.0,ctime=1679202233
name: NogGamingVM
net0: virtio=MAC,bridge=vmbr0
numa: 1
onboot: 1
ostype: win11
scsihw: virtio-scsi-single
smbios1: uuid=UUID
sockets: 1
tpmstate0: Samsung_2TB_SSD:vm-104-disk-0,size=4M,version=v2.0
vga: virtio
virtio0: Samsung_2TB_SSD:vm-104-disk-2,backup=0,cache=writeback,iothread=1,size=768G

I have a bunch of other VMs, most of them have only 1 core allocated and are just seated idle. The only problem only occurs when my cousin is playing. The promox CPU goes to near 100%, even when the VM only has 2 cores attached.

As you can see we are even using different SSDs. Is there any suggestion?



Thanks!

 

[leesteken]

Maybe 5 cores are busy with games and Parsec and Proxmox also needs a core and you need a core for the network. Your CPU will have all 6 cores busy and can therefore not boost/turbo and will at best run at 2.8GHz. Meanwhile Proxmox needs to give some time to other VMs as well (and Hyper-threading won't really help) and spend time on I/O and some emulation.
Maybe all this will work more smoothly when you give each gaming VM only 1 core (can you please test this)?
Maybe you just need a better/bigger CPU to run multiple VMs at a 100% (as running any resource at 100% is contrairy to virtualization and increases latency)?

 

[brnogu]

I will try thanks for the insights. So I can imagine that I will buy a Christmas present this year to myself

 

[gfngfn256]

and Hyper-threading won't really help

The i5-8400 anyway has no hyper-threading (source Intel).

I agree totally with your analysis, and will just add that he also has separate PCI (GPU) passthrough going on both to his own VM & to his cousins.

I must be honest, he should be proud he got it running at all!

But he is going to need something a bit more powerful than that 2017 six-thread snail with its dated MB/chipset.

 

[brnogu]

The i5-8400 anyway has no hyper-threading (source Intel).

I agree totally with your analysis, and will just add that he also has separate PCI (GPU) passthrough going on both to his own VM & to his cousins.

I must be honest, he should be proud he got it running at all!

But he is going to need something a bit more powerful than that 2017 six-thread snail with its dated MB/chipset.

Ahah. I will definitely buy a present to myself this year. I hate this new E - Cores that most of Intel CPU have. I’m thinking about going to AMD
AMD Ryzen™ 9 9950X or AMD Ryzen™ 9 9900X

I have a lot other VMs running. The thing is, I would love to build a new VM / container only to process ollama, but I might need 3 GPUs :,(

2 for the two gaming VMs + 1 for ollama. Unless I run it inside one of the windows machines.

Btw thank you very much for all the insights so far

 

[leesteken]

AMD Ryzen™ 9 9950X or AMD Ryzen™ 9 9900X

I have a lot other VMs running. The thing is, I would love to build a new VM / container only to process ollama, but I might need 3 GPUs :,(

I believe all AM5 processors come with integrated graphics. But only the X570(S) of the old AM4 platform supported PCI(e) passthrough from more than one or two slots. I don't have much experience with AM5 yet, so make sure to check the IOMMU groups before buying any particular motherboard. My 5950X (on X570S) can run multiple game VMs with GPU passthrough, but it's getting out of date (but still fast enough for me).

 

[Azunai333]

I believe all AM5 processors come with integrated graphics.

No, some have no integrated graphics. If your CPU ends with F (like AMD Ryzen 5 8400F), then you don't have one.
All others without the F suffix have one.

 

[gfngfn256]

I hate this new E - Cores that most of Intel CPU have

I'm running a Proxmox instance (at home) on an i7-13700H (6 PCs, 8 ECs & 20T total) on a Minisforum PC for about 18 months with NO issues. Numerous LXCs & VMs & I'm very happy. I don't do any GPU passthrough, & I've always stuck with Intel (not sure why?!).

 

[leesteken]

No, some have no integrated graphics. If your CPU ends with F (like AMD Ryzen 5 8400F), then you don't have one.
All others without the F suffix have one.

Thank you for correcting me. Do you know if you have more PCIe lanes (and therefore passthrough on ones without graphics, or less than the usual when they have graphics (like AM4)?

 

[Azunai333]

Do you know if you have more PCIe lanes (and therefore passthrough on ones without graphics, or less than the usual when they have graphics (like AM4)?

TLDR: I'm afraid i don't know.

I haven't looked that deep into it. As you wrote passthrough is all about the mainboard, but I stopped looking for an upgrade as the newer CPUs currently are not good upgrades in my case...
Also on the server side, I am still using used Intel CPUs.