Q. What's the Relative weight setting in a Hyper-V virtual machine (VM)?

A. Each Hyper-V guest VM can be assigned one to four processors. Optionally, you can assign an amount of CPU resources that are reserved for the client and a cap on the amount of processor that can be used. Another option is the Relative weight, but it may not be obvious initially what it is or how it works.

While absolute percentages of processor can be useful, there may be times when you don't want to reserve or limit CPU—you just want to set which VMs have priority in times of processor contention. This is what the Relative weight does. A VM with a weight of 200 would get twice as many processor time slices as a VM with a weight of 100. The weights of all the VMs are added together and then the weight of the VM is divided by the sum to calculate the relative amount of processor for a VM. If you want a VM to get processor priority, give it a higher weight than other VMs.