Core/vCPU question

[martijnk]

Hello,

Sorry posting a lot of questions lately But I couldn't find the exact answer.

So I have Proxmox nodes with 12 cores / 24 threads. When I create a VM I can pick the amount of sockets, cores and vCPUs.

So with sockets and cores would I always enter what the machine has physical? So e.g. most VMs will only get 1 or 2 vCPUs, would I still give those VMs 1 socket and 12 cores? Or would I give it 1 socket, 2 cores, 2 vCPUs?

Thanks!

 

[jsterr]

Cores can be the maximum of your hosts cpus (with Hyper-Threading double value)
vCPU value is the current given vCPUs to VM.

So if you put in Cores 12 and vCPU 4 you can potentielly upgrade cpu in your VM via CPU-Hotplug to a total of 12 vCPUs without rebooting vm afaik.

Check this out: https://forum.proxmox.com/threads/sockets-vs-cores-vs-vcpus.56339/#post-259553

 

[martijnk]

Cores can be the maximum of your hosts cpus (with Hyper-Threading double value)
vCPU value is the current given vCPUs to VM.

So if you put in Cores 12 and vCPU 4 you can potentielly upgrade cpu in your VM via CPU-Hotplug to a total of 12 vCPUs without rebooting vm afaik.

Check this out: https://forum.proxmox.com/threads/sockets-vs-cores-vs-vcpus.56339/#post-259553

Thanks that makes sense! So it has no negative impact on performance when I give my VM 24 cores and one vCPU, against 1 core and 1 cpu.

Question answered!