P55 mobo's dont have a FSB they have whats called a base clock. I think (might be wrong though)all i5 and i7 cpu's have a base clock (same as FSB kinda) of 133MHz which is then multiplied by 20 to get speeds like 2.66GHz.
Shedman is right, the latest intel CPUs use a base clock instead of fsb. I personally dont understand the difference but Im no expert, but you basically have a smaller base clock and higher multiplier than the older CPU's
e.g. My E8400 would run 4GHz at 500MHz fsb and an 8x multipler
My i5 750 runs 4GHz at 200 base clock and 20x multiplier.
Guessing the change is due to the Nehalem architecture but Im not sure of why its changed