Performance problems when running the FMS in a virtual environment (4353139)

FMS environment:

FMS is a single VM with embedded mySQL database. We started it initially with 4GB ram, 2 processors running version 5.2.2. The console ran a bit slow, but was acceptable given that at that time we weren't even at the minimum requirements. As we added agents it started to slow down. Increased to 6 GB ram, performance went back to initial. Increased a few weeks after to 8 GB ram due to another drop in performance, but did not help any. Upgraded to 5.2.3 also did not help performance.

The VM was then given 4 processors, and 12 GB RAM. FMS service would start, run for approximately 5 minutes, and stop. Resized the Pagefile for windows from 6 GB to 19.3GB. Server would start and run, but after about 10 minutes the performance is at a crawl. Have restarted several times (service and OS) and still crawls. CPU is basically maxed out, and Pagefile usage is at 17.9 GB.

What can be done to improve performance?