How to enable hyper-threading on nehalem (Xeon5500 series) CPU?

[raoulst]

Hi,

I try to enable hyper-threading on my new HP DL380 G6 servers running ESX 3.5, but although it shows up in the configuration tab as "enabled", no VM can detect it.

And yes, it's enabled in the BIOS.

Any ideas?

raoulst

[depping · Accepted solution]

Why should a VM detect it? It's not presented to the VM as a feature. It increases scheduling options on a vmkernel level but that's about it.

Duncan

VMware Communities User Moderator | VCP | VCDX

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[raoulst]

Hello Duncan,

thanks for your answer which would explain what I see. Do you have any idea, where I can find information about this in the VMware documentation?

Raoulst

[AndreTheGiant]

To see if HT is enabled also on ESX, go on configuration / Processor / Properties and verify the flag.

If it works, on the same page you must see that Logical processor = 2 x Processor Core per socket x Processor Socket

Andre

[raoulst]

Hello Andre,

yes, that shows up correctly, just wondering about the not showing up in the VM part.

Raoulst

[AndreTheGiant]

At VM side you cannot see CPU, cores or HT... you see only vCPU, that are simple logical core...

Andre

[raoulst]

Hi,

seems I simply got that wrong. Obviously there is no ht presented to the VM.

Thanks for your help,

Raoulst