First off, what were the specs of the actual machine. Second, what are the specs of the virtual machine? Are they comparable?
If you are using Vmware, will the administrator add another virtual processor for you? Or has he set processor speed limitations? Have you checked 'free -m' to see if the process is causing swappiness? Maybe he could add some ram for you.
More information is needed to be able to pinpoint the solution. But any of these things will have an effect on the processing time. But sadly, it should also be stated that you are going to lose performance when you go from metal to virtual.