Hi Jesse,
If your concern is just about processing power, I wouldn't be afraid of going virtual. Just pay attention to certain technical points.
On standard configurations, we used to consider losing about 5% to 10% of processor capacity in virtual servers when compared to physical. It should be even less with latest ESX versions. As we usually move from old hardware to newer processor generations, the gain is still huge!
Of course, if you have a very heavy compile workload for which you installed a special physical machine with lots of processors and gigs of memory, going virtual needs to be tested. And if you use any special hardware devices, it also needs to be analyzed. Finally, you need to take care of the sizing of your hosts to avoid having your VMs fighting for resources.
You can make a first try for example with a physical server you have, run you workload physical, then install the free ESXi and replay your test in a VM. This could give you a good idea of what you should obtain in real conditions.
Good luck!
Regards
Franck
