If you use both --cpulimit and --cpus to set the CPU limit for a virtual machine or container, the smallest limit applies. For example, running the following commands on a server with 4 CPUs, 2 GHz each, will set the limit for the container MyCT to 2 GHz:
# prlctl set MyCT --cpus 2 # prlctl set MyCT --cpulimit 2000m
