How many vCPUs per physical core?

bruh21

Just wondering, how many vCores are assigned per actual core? I know providers say fair share, but how many neighbors would you normally have on each core?

jlay

It varies, a couple dozen isn't that unusual. It is on the high end though

Anywhere from one to that, I'd guess.

High frequency CPUs with a lot of cache can handle a lot more per-core. It comes down to a certain amount of overlap/Tetris.

How much monitoring/QoS do they want? Can their customers appreciate something consistent, but measurably slower?

The host might not even bother to pin - leaving it up to the kernel

edit: It gets really complicated when you consider things like NUMA

edit2: it gets even more complicated when you consider what 'on a core' really means.

They tend to share pools of cache, activities on another core impact the performance of yours.

The CPU core and 'hyper thread' are often treated as separate and I don't think they should be

bruh21

@jlay said:
It varies, a couple dozen isn't that unusual. It is on the high end though

Anywhere from one to that, I'd guess.

High frequency CPUs with a lot of cache can handle a lot more per-core. It comes down to a certain amount of overlap/Tetris.

How much monitoring/QoS do they want? Can their customers appreciate something consistent, but measurably slower?

The host might not even bother to pin - leaving it up to the kernel

edit: It gets really complicated when you consider things like NUMA

edit2: it gets even more complicated when you consider what 'on a core' really means.

They tend to share pools of cache, activities on another core impact the performance of yours.

The CPU core and 'hyper thread' are often treated as separate and I don't think they should be

thanks for the answer
i wonder how many are assigned from top providers like racknerd and nexusbytes