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sluge
Enthusiast
Enthusiast

CPU utilisation

Hello

I created on my server a VM with one logic CPU because I need FT feature enabled, but my server has 2 sockets of Intel Xeon, so, it looks like actually only one hardware CPU will work( It is true ot the second one will works too?

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5 Replies
depping
Leadership
Leadership

FT currently only supports 1 vCPU. The amount of physical CPUs doesn't matter though,

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sluge
Enthusiast
Enthusiast

yes, I agree with you. But does it means that on my server only one CPU would actually work on and thwe secondary one would be idle?

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dhabbetichandra
Enthusiast
Enthusiast

That virtual CPU utilizes both Physical CPUs

Jvdp
Enthusiast
Enthusiast

A virtual CPU is not the same as a physical CPU. As you say you have 2 sockets with a Xeon, you probably have 2 quad (or six-core) CPUs. With hyperthreading you will see 16 logical CPU's (if you go to Host > Summary in the vSphere Client). Your VM with 1 vCPU will be scheduled on all the physical CPU cores (or logical CPU's). So you cannot actually tell what VM is using what physical core at a single time, as it is scheduled by ESXi. (to explain it clearly in an easy way).

And it is indeed correct that if you want to use FT, you can only have 1 vCPU in your virtual machine.

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milton123
Hot Shot
Hot Shot

You can't specified which core will be use. It may be all of core use or not but Your VM  will be scheduled with 1 vCPU,

Cheers, Yours Udin