Major lag with all games. Is my PC ok to use?

[NKF98]

i don't think his hard drive is the issue, and nor is it yours morgoth

[DeeKay]

The hard drive could cause stuttering in a game, but I do agree that it most likely won't cause low framerates.

whiskey, what games are you trying to run? I have a similar CPU (Phenom II X4 955 @ 3.5 GHz) and can play maybe half of my games at full speed.  Gamecube games run pretty well, but you'll have a bad time with most Wii games.