there is a chance that neither will hit 2.5, depending on the board you may be more likely to hit it with the 3200, but neither is gauranteed. Depends on cooling and voltage and on luck of the draw. And yes it doesnt matter whether you have ht at 2 and fsb at 400 or ht at 4 and fsb of 200 it should be fine, and you dont have to wory about 800mhz as the limit, nf3 boards can get to 900mhz and sometimes higher, so you could probably get away with an ht of 4 with an fsb over 225, and certianly to about 220, much beyond that and you may have to go to 3, though on some boards you can get to 240 and 250 at 4.