How many cores to allocate to a virtual machine?

Question

KVM

On a dedicated server, I raise a virtual machine on Windows, when creating, you can specify any number of cores, does this affect performance?
The server is:

Intel  i7-4790K
i7-4790K	4/8t  
4,0 / 4,4 GHz	32 GB of RAM
DDR3 1333 MHz

How many cores should be specified in the virtual machine?

Answer 1

specify the number of cores that you want to allocate to the
virtual machine, you cannot allocate more than 8 cores, since you have only 8 cores on the server