With AWS, I found this info from tableau recently:

An AWS vCPU is a single hyperthread of a two-thread Intel Xeon core for M5, M4, C5, C4, R4, and R4 instances. A simple way to think about this is that an AWS vCPU is equal to half a physical core. Therefore, when choosing an Amazon EC2 instance size, you should double number of cores you have purchased or wish to deploy with.

https://onlinehelp.tableau.com/current/server/en-us/ts_aws_v...

Don't know how true it is, but there's no reason for me not to trust what Tableau has to say.