Nested virtualization very slow: Intel vs AMD thoughts

decibel83

Renowned Member
Oct 15, 2008
210
1
83
Hi.
For the purpose of creating a testing and development environment I need a virtual machine which hosts a Virtualbox installation.
For this reason I enabled the nested virtualization following instructions at https://pve.proxmox.com/wiki/Nested_Virtualization on two different physical hosts:
  • AMD Ryzen 9 5950X 16-Core Processor, 32 vCore (Hetzner AX101), CPU mark 46.175
  • Intel(R) Xeon(R) CPU E5-2650L v2 @ 1.70GHz, 40 vCore (HP Proliant DL380p Gen8), CPU mark 7.475
I installed a Debian Bullseye virtual machine, enabled the nested virtualization and installed Virtualbox in it.

Well, Virtualbox's virtual machines on the AMD Ryzen host is pretty usable (not super-fast, obviously but they are usable without critical problems), but on the E5-2650L host Virtualbox is simply hanged and unusable: Windows 10 installation takes hours, and after it is simply unusable.

I completely know that the E5-2650L CPU is pretty old and not so fast, but I was not thinking about this such slowness, so I have a couple of questions:
  • is this behaviour normal and expected, because the E5-2650L is slow and old?
  • is AMD really better than Intel processors for nested virtualization purposes?
  • would a newer Intel CPU (like i9, for example) be faster than the Ryzen?
I am making these questions because I am thinking about buying or assembling a new host expecially for nested virtualization purposes, so I need to choose between Intel i9 and AMD Ryzen 9 processor.

Thank you very much!
 
Hello.
  • is this behaviour normal and expected, because the E5-2650L is slow and old?
Yes. Also Virtualbox is not the most efficient way of virtualization and windows is not really resource-saving.
  • is AMD really better than Intel processors for nested virtualization purposes?
This shouldn't make a great difference except for the fact that most amd cpus have more cores for a cheaper price than intel.

Notice: Windows 10 with WSL2 and Windows 11 with WSL either does not work on AMD or has a bad performance. Kernel 5.15 should have made the support a bit better.

  • would a newer Intel CPU (like i9, for example) be faster than the Ryzen?
maybe, probably also more expensive than a ryzen. compare them.
 
Last edited:

About

The Proxmox community has been around for many years and offers help and support for Proxmox VE, Proxmox Backup Server, and Proxmox Mail Gateway.
We think our community is one of the best thanks to people like you!

Get your subscription!

The Proxmox team works very hard to make sure you are running the best software and getting stable updates and security enhancements, as well as quick enterprise support. Tens of thousands of happy customers have a Proxmox subscription. Get yours easily in our online shop.

Buy now!