How to enable(use) AVX/AVX2 CPU instructions in ESXi environment ? ( there isn't vCenter. )

[DCYun]

My server (H/W) have AVX and AVX2 supported CPUs and installed ESXi 7.
However, a Linux VM on the ESXi environment, When running the "cat /proc/cpuinfo | grep -i avx" command, I cannot check the results.

If have vCenter, can enable EVC mode, but I cannot find the configuration in ESXi environment. ( i don't use vCenter. )
In this case ( ESXi only ) , can I change to use AVX and AVX2 instructions with ESXi only?

[bluefirestorm]

I am pretty sure that virtual hardware version 11 is required for AVX2 to be supported inside VMs with an Intel CPU that supports it (Haswell or newer). For AVX, even if it is as old as version 8 should support AVX. I don't know virtual hardware version requirement for AMD CPUs.

So check the virtual hardware version of the Linux VM first.

Otherwise, post a vmware.log of the VM. Perhaps you have some masks applied before and forgot about it.

 

[DCYun]

 

Thank you for answer.

First, I temporarily created a vCenter and changed the 'EVC mode' setting.
Afterwards, avx and avx2 became available.

 

I will test your answers later if I encounter the same problem.

 

Best Regards,

[IT Support Manager]

I tried changing the cpu generation in the EVC mode section from Intel® "Nehalem" Generation (Xeon® Core™ i7) Intel® to "Westmere" Generation (Xeon® 32nm Core™ i7).  the VM would not start afterwards.   Is there a trick to changing this value?

[bluefirestorm]

AVX requires Sandy Bridge or newer CPU.
AVX2 requires Haswell CPU or newer CPU.
Westmere is the one before Sandy Bridge.

If you want both AVX and AVX2, the CPU required is Intel Haswell or newer. No amount of tricks of changing the EVC mode will bring AVX/AVX2 to life if the silicon does not have it.