The Intel 12th Generation (Alder Lake) CPU is the first Intel consumer CPU that introduces a new hybrid big.LITTLE CPU architecture. 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.
These new hybrid Intel CPUs have also become the defacto standard for the Intel NUCs starting with the 12th Generation Intel NUCs (Dragon Canyon, Wall Street Canyon & Serprent Canyon), which were released last year. While the ESXi scheduler does not support or understand this new consumer CPU architecture, it can function with ESXi but does require an ESXi kernel boot option, which I have documented HERE, that tells ESXi to ignore the CPU differences.
While this has been an acceptable workaround, there are no guarantees on how the ESXi scheduler will behave. Furthermore, you will also not benefit from Hyper-threading (HT) on the P-cores as the E-cores do not contain HT-enabled cores and hence HT is also disabled by ESXi. A slightly better workaround is to actually disable the E-cores, which would give you uniform CPU P-cores and also access to HT. During my initial investigation, I was never able to figure out how to disable the E-cores within the Intel NUC BIOs and I had assumed it was just not possible.
I recently had re-inquired about this configuration change and came to learn that it is possible to change both the P-core and E-core settings within the Intel NUC BIOs, it was just not very intuitive!
Depending on your needs, you might prefer to disable the P-cores to run on the lower power E-cores or get the full benefits of the P-cores by disabling the E-cores.
Step 1 - Press F2 during the boot up which will launch the Intel NUC BIOS and then navigate to the Power, Performance and Cooling tab. Change the default value of the External Ambient Temperature Tolerance to User Defined and this will actually enable the Performance setting to be configurable.
Step 3 - Finally, you can adjust the various CPU settings including the number of active both P-cores and E-cores, which by default is All. To disable all E-cores, change the value from All to 0 and vice versa if you wish to disable all P-cores.
Press F10 to save the settings and after you reboot, you no longer need to add the additional ESXi boot option as the cores will now be uniform and ESXi will function normally like a typical uniform x86 CPU.
UPDATE (04/05/23) - If you have an Intel NUC 12 Enthusiast, make sure you have updated to at least BIOS SN0056 and the option will show up under the Performance tab as shown in the screenshot below.