L1 Terminal Fault mitigation setting does not take

[jeffj2000]

I have a Dell R740 with the latest BIOS. I am swapping them with R730s. Both are running ESXi v6.5U2h.

I noticed my R730s had the warning about the the L1 fault and so I set this to True.

VMkernel.Boot.hyperthreadingMitigation

My R740s never gave the CVE warning. I set the mitigation setting anyway and rebooted. However, it still had 72 Logical CPUs. This is a 36core box.

My R730s went from 72Logical CPUs to 36 after the fix.

Is the BIOS on my R740 not susceptical and thus the setting wont take?

[grinch3334]

If the 740's have the 2nd Gen Xeon Scalable, the 62xx series, they are not vulnerable to L1tF vulnerability. The 740's can have 1st or 2nd gen. Not sure, but maybe vshpere is smart enough to not disable hyper threading if it sees a CPU that is not impacted?