I had a few surprises when I began replaying a production workload on a virtual server. I'm using the same workload I captured from a production server and replayed on a physical server in different scenarios. The first virtual test was on a 32 bit server hosted on a VMWare box with CPU affinity turned on. A limitation of virtual servers (at least for now) is that they are limited to 4 CPUs.
The first surprise was that the replay was faster than the 4 CPU test on a physical server, 3:07 virtual compared to 3:40 physical. The second surprise is that the total number of transactions appeared to have dropped.
I'll be looking into this to see what I'm missing, and I'll post more details soon.