How can VMs use more cpu than host's cpu speed? (VM has 1 vCPU)

Hello everyone.

I have a question about using the vsphere client and wonder why it looks like this.

VM GCAMS-01 has 1 vCPU and it's host has 12 core. Each core has 2.66GHz clock speed.

It seems GCAMS-01 can use cpu from 0 to 2660MHz but it uses 2819MHz now.

Although it's cpu resource is set unlimited, but it Should not be less than 2660MHz?

Or does the speed of the vCPU have anything to do with the speed of the physical cpu?

Thanks.

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