2 servers on the same computer?

Does anyone know how to do this? I assume it’s possible, but how?

Note: Yes, it’s just one computer. I own the computer in question.

For this, the server should have at least 4.00 GHZ Quad core Processor and 8+ Gigs of System Memory. (Twin Ethernet ports Recommended)

set the affinity of both Srcds Copies to Separate cores (Maybe 2 cores per copy running)
And Shutting down every unneeded process (Including Explorer.exe(It can be started again later by “Newtask” => “Explorer.exe”).)
and set the Priority of both Copies to “Real-Time” by right clicking on each process and going to “Set Priority”

Or just Rent one server and run the other from home… That’s a good solution right there