I would like to understand how to select how many CPU cores should I use.

[teokoul]

Hello there,

First time I use Proxmox.

I finish with the setup I want: INSTALL//GPU PASSTHROUGH//REMOTE DESKTOP etc.

I would not have done anything without the help of this community.

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Now I would like to understand how to use my CPU. I have a Ryzen 7 1800X CPU and it have 8 cores.

How many VMs could I build with this CPU?

How to choose how many cores and sockets add on a VM?

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Thank you for your time!

 

[ph0x]

How many VMs you can run with your hardware depends on the load they generate.
In general, one core should be enough for most machines since the load is distributed among all cores, anyway. If you encounter a certain machine hitting 100% cpu usage for a longer period then you could consider adding another core.
Now, the combined load defines how many machines can run concurrently. Keep an eye on the load average of the host. As long as it stays below your core count, no machine has to wait for cpu time, which means that there is still room for another machine.
Keep in mind though that in a cluster the load of a failed node has to be distributed to other nodes, so they should have a reserve in cpu and ram.

 

[Dunuin]

Like ph0x said, if most VMs are just idleing you can for example run 64 VMs with 1 core each or 8 VMs with 7 cores each and so on. Just keep in mind not to give a VM the maximum number of cores so it can't block the host itself by utilizing the complete CPU.

 

[teokoul]

How many VMs you can run with your hardware depends on the load they generate.
In general, one core should be enough for most machines since the load is distributed among all cores, anyway. If you encounter a certain machine hitting 100% cpu usage for a longer period then you could consider adding another core.
Now, the combined load defines how many machines can run concurrently. Keep an eye on the load average of the host. As long as it stays below your core count, no machine has to wait for cpu time, which means that there is still room for another machine.
Keep in mind though that in a cluster the load of a failed node has to be distributed to other nodes, so they should have a reserve in cpu and ram.

Like ph0x said, if most VMs are just idleing you can for example run 64 VMs with 1 core each or 8 VMs with 7 cores each and so on. Just keep in mind not to give a VM the maximum number of cores so it can't block the host itself by utilizing the complete CPU.

Thank you for your reply.

Trying to understand.

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So, now I have a 8-core CPU.

When I creating a VM it ask how many cores I want. I am able to create 4 VMs with 2 cores each (and this is the limit) ?

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When a software recommend 2core - 2GHz what settings I should to choose to run correctly?

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I want to clarify that I am not a computer engineer (I have a lot of experience on CS).
I start to build my Proxmox Server - two months ago - with the simply question on google "How to build a server". And here I am

 

[Dunuin]

So, now I have a 8-core CPU.

When I creating a VM it ask how many cores I want. I am able to create 4 VMs with 2 cores each (and this is the limit) ?

If that CPU got hyperthreading (16 threads) that should be fine and run with maximum performance, even if every VM is working at 100% CPU utilization at the same time. If the VMs are mostly idleing you could create way more VMs (for example 32 VMs with 2 cores). It all depends on how busy your VMs are. You need to monitor the CPU utilization of the Proxmox Node itself and look that it will never be stuck at 100%.

When a software recommend 2core - 2GHz what settings I should to choose to run correctly?

Try it with 1 core first. If you think that feels slow add another core. You can always change the number of cores later.