The folks over at SimplyNUC has recently launched an exciting new Edge-focused product line called the extremeEDGE (EE) Servers and I recently had the opportunity to try out their latest 3000 Series (3rd generation of their EE platform) in my homelab for some testing.
After debugging a recent issue with using VMware Workstation and Intel Hybrid CPUs, it gave me an idea about an experiment to try with ESXi and Intel Hybrid CPUs.
As a refresher, starting with the Intel 12th Generation (Alder Lake) CPU, a new hybrid big.LITTLE CPU architecture was introduced for consumer Intel CPUs. This new hybrid Intel CPU architecture integrates two types of CPU cores: Performance-cores (P-cores) and Efficiency-cores (E-cores) into the same physical CPU die. For more information about this new hybrid Intel CPU design, check out this resource HERE. The ESXi scheduler does not and has no current plans to support this new Intel Hybrid CPU architecture, especially as this type of architecture is nowhere to be found in traditional Enterprise datacenters and is only limited to Intel Consumer CPUs.
The current recommendation to work around the non-uniformity of the CPU cores is to either disable the E or P-cores within the system BIOS, thus making the system "uniform" and allowing ESXi to run like a normal x86 system. While you can apply a workaround to have ESXi ignore the non-uniformity of the CPU cores, in addition to the non-deterministic behaviors, random PSOD can also occur due to scheduling across two different types of cores.
I was curious to see whether applying ESXi CPU affinity on a VM using Intel Hybrid CPU Cores might yield a different outcome?
There have been some recent reports from users observing performance issues when running VMware Workstation on Windows 11 along with using recent Intel (12th Gen and later) Hybrid CPUs, which introduces a new hybrid big.LITTLE architecture for Intel's x86 consumer CPUs.
This new Intel Hybrid CPU contains two types of CPU cores: Performance-cores (P-cores) and Efficiency-cores (E-cores) into the same physical CPU die, which follows a similar design to Apple Silicon CPUs. For information about the new Intel hybrid Intel CPUs, check out this resource HERE.
At first glance, most users had assumed this was due to Virtual Machines being scheduled to run on the less powerful E-Cores, this was problematic even for non-VMware use cases and with the recent introduction of Intel Thread Director, this was supposed to have been improved with Windows 11.
However, after some internal testing, the Intel Hybrid CPU may not actually be the culprit.