vCPUs and Cores question

kast0r

New Member
Jun 29, 2022
11
0
1
Hello,

First of all here are the specs of my server:
  • i5-12600K
  • 64GB RAM
  • NVME 1TB
  • 3x 500GB SSD
  • 1x 2TB HDD
Let's say I want to create a dedicated game servers. The CPU requirement is anything with 4+ cores.

I put 4 Cores on 1VM x 4 for a total of 16Cores (16CPUs)

Does it means I have no more room to create other VM as I used all the CPUs available ?

I'm still new to Proxmox and I can't get it in my head how it works when I read people saying it's 6:1 , 4:1 when I basically spend all the 16Cores on 4VMs.

Thanks!
 
Apr 3, 2022
104
37
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You can overcommit. (Provision more RAM and vCPU than is available.) And depending on your workload, it might even be a good idea.

Also, don't get hung up on hardware requirements. I run plenty a VMs with only 1 or 2 vCPU that handle everything I can throw at it.

The beauty of running a Hypervisor is that you can play around and adjust configs... then monitor usage to see how it behaves.
 

bobmc

Well-Known Member
May 17, 2018
582
91
48
65
It all depends on how resource intensive each VM is going to be. My system has 12 cores/24 threads and in total I have 32 cores allocated to running VM's and containers and the system barely breaks a sweat with the average CPU load on the host being below 10%

However, none of my VM's run anything CPU intensive so your experience may differ.
 

Dunuin

Famous Member
Jun 30, 2020
6,682
1,550
149
Germany
That CPU only got 6 performance cores. So if you want the full performance you shouldn't allocate more than 6 vCPUs to all VMs combined. Otherwise the load will also use the slow efficiency cores. You can use more than that but your game servers will be slower then as PVE will switch those virtualization processes between the fast and slow cores. And hyperthreaded threads aren't as fast as real cores. Not sure how well PVE manages load between performance and eficiency cores. Linux had problems with that in the past.

It all depends on how resource intensive each VM is going to be. My system has 12 cores/24 threads and in total I have 32 cores allocated to running VM's and containers and the system barely breaks a sweat with the average CPU load on the host being below 10%

However, none of my VM's run anything CPU intensive so your experience may differ.
Similar here. Got 16 cores / 32 threads with 60 vCPUs assigned to VMs/LXCs but CPU utilization is usually just around 5 and 20% as I'm mostly limited by not enough RAM to really utilize that CPU with my services (would needto upgrade from 64 to atleast 128GB RAM to be able to run all VMs in parallel).
 
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