In computer FPS depends on how fast your application/program is running if it runs at 100 its running with no framerate drops at all.
But if you want it your way keep it your way.
Shadow, I'm going to tell you this right now: shut up.
You don't know what you're talking about.
I was able to run a singleplayer GMod server with a 3.0 GHz Pentium 4. A quad-core doesn't even utilize all the cores available when running a Source game. You don't need a super-powerful PC to run GMod well.
Also, it's not 100 FPS. It depends on your monitor's refresh rate, which is commonly 60, 72, 75, or 120 Hz, so if you have a 60 Hz monitor, if it was running at 0-59 FPS, it would be noticable (probably not as much near the 30-59 mark). If it runs faster than 60, you won't notice it, because your monitor can't let out more than 60 frames a second.
God damn, learn about PC's first before you try to post stuff like that. Otherwise, you'll look like an idiot.