High cook times when built on virtual machines

When we run our build on bare-metal machine in location A, the cook times are 20 mins
When we run our build on a Virtual Machine in a datacenter in location B, the cook times are 40 mins.

We have no DDC enabled and the cook works even with disabled network adapter in Virtual Machine. This means the cook is not doing any operation to access network and hence getting slow for that.

We are running incredibuild.