Hello,
I want to install 4 to 5 system ( Linux or solaris ) in vmware workstation for oracle database testing purpose. processor is i5 2500/ Mobo DH67CL / 16 GB Ram. it this feasible.
Your specs should be fine for that kind of testing, the main thing in a vm environment is ram and you have plenty of it.
Agree and want to add that the hypervisor will manage which VM gets which CPU(s). If too many VMs will have high CPU load, then you will see latencies. But for running, feel free to have 20 VMs with 512MB RAM each. But when you cannot control the host due to latencies (many VMs doing CPU work), you will pull your hair.
PS: the Xeon CPUs used in server enviroments are nothing more than the regular i5/i7s. They are just tested more, could be the most efficient samples from the line and ECC memory is enabled.