How does Proxmox use P and E cores?

With new x86 processors I want to see how Proxmox deals with these different types of cores. I use a test system with a 12900k to test how Proxmox with allocate P and E cores when using VMs and containers. I also test to see if E cores could be used to save power on a system.

This testing was done on Proxmox 7.4 with the optional kernel 6.2 in June 2023 before Proxmox 8 was released.

Thanks to @Patryk122PL for letting me know how to pin containers to cores. To do this, edit the containers config file at /etc/pve/ct/(ct-ID).conf, then add this line to the config file: lxc.cgroup2.cpuset.cpus: 0-7. A VM can also have its cores pinned to specific cores on the host using under the CPU settings on the Processors options page.

0:00 Intro
1:00 How the kernel uses P and E cores
3:42 VM core allocation
5:09 Tying to use E cores to save power
6:48 Container core allocation
8:29 Conclusion