???? a computer is much faster than a PS2, except a computer is always multitasking, so that would make it seem slower, but ultimately, it depends on your computer. the slower ones would run FFXI slower (obviously) and the faster ones would run the game faster (obviously) but i begin to wonder how fast you want it to be played
if u mean lag, it depends on the connection and the video card and video settings and a lot of other things. but, PS2 will run it very well, and the PC will run it very well, but with (potentially) better graphics.