hmmm I get 1 minute at most load times at highest detail at 1024x768 with my computer: P4 1.4 w/ 384 PC800 RDRAM w/ GeForce2 Ultra. The only problem I experienced on single player was the Yavin Swamp mission in which my fps slowed down a tremendous amount compared to the other missions (fog, and all those brushes kills fps).
Multiplayer = bad on high detail LOL and worst on highest detail. Sometimes my game stalls for about 3 seconds or I get sound lockups grrrrrrrrrrrrrrrrrrrrrr...
But, all in all, single player was played smoothly on my comp