If disabling the Efficient Cores (in BIOS) on your new NUC system doesn’t help you to install ESXi 8 on your new NUC – then read on!

Recently I got my hands on a new Asus NUC 14. The first thing that I went to do was to install ESXi 8 on it. I already knew that there would be some problems with the CPU since it has multiple core types – that is: E-Cores (efficient) and P-Cores (Performance). But according to the specifications this CPU generation (Intel 14^th aka Meteor Lake) also has third “Low Power Efficient” core type.

So, the CPU (Intel 155H) looks like this:

6x “Performance-cores”

8x “Efficient-cores”

2x “Low Power Efficient-cores”

To install ESXi on the machine I headed to the blog of William Lam (who has so many great resources on ESXi lab hardware and lab “how to”) – in this great article he shows two ways of getting ESXi to run on “multi core” type CPUs : ESXi PSOD due to GP Exception 13 in world with Intel 13th Generation CPU (williamlam.com).

So, I started with option 1 from the above article (Disable Efficiency Cores, within system BIOS) – but that didn’t seem to work – after some investigation I actually found out that the “new” third type of cores (Low power Efficient cores) doesn’t get disabled – so this concludes that option 1 doesn’t work for meteor lake.

Option 2 on the other hand does work (adding “cpuUniformityHardCheckPanic=FALSE”, to the boot option). But the disadvantages here is that you are allowed to use all cores and the three core types are working at different speed – and that brings me to the primary reason for this article – the overview of the cores (number vs. type).

So if you go to another great article of William Lam: Experimenting with ESXi CPU affinity and Intel Hybrid CPU Cores (williamlam.com) then you will see how we are able to use CPU affinity to “lock” the different virtual machines to the cores of your desire.

In the article you see that the first 4 cores (0-3) are Performance cores and the rest of them are Efficient cores. – But on the Gen14 Meteor Lake CPU it’s quite different!

The Intel Gen 14 CPU (Meteor Lake) looks like this:

Performance cores = 0,9,10,11,12,13

Efficient cores = 1,2,3,4,5,6,7,8

Low power efficient cores = 14,15

I discovered this by running some CPU performance benchmarking on the different cores as you can see here:

So, there you have it – the list of the different cores on the Intel 14^th gen and the reason why it doesn’t help to disable the E-Cores when installing ESXi 8 on it 😊