Can I run a Minecraft multiplayer server and client on the same machine?
Solution 1:
Yes, I've done this with a much less high-powered PC and about 8 or 10 users connected. It worked fine.
The biggest problem with Minecraft servers (apparently) is that if your players explore too far, your memory footprint will get ridiculous at some point. I didn't see any problems in this area, though - most of my players stayed near the spawn for the most part.