FSB and memory speeds

[ondrugs]

i am about to ask a very noob question

why do some mobo manufacturers advertise hight FSB speeds (like 1066 or 1333), but lower memory speeds (DDR2 667 or 800).
i thought the whole idea would be to much up all the FSB speeds?

 

[dagger]

i am about to ask a very noob question

why do some mobo manufacturers advertise hight FSB speeds (like 1066 or 1333), but lower memory speeds (DDR2 667 or 800).
i thought the whole idea would be to much up all the FSB speeds?

1:1 ratio is ideal. But don't worry about matching up. Syncing makes almost no difference in performance anyway. Just get whatever ram you can get a good deal on.

 

[tjoepie]

The FSB of the CPU is quad pumped so 333Mhz x 4 i= 1333, but DDR2&3 are x2 so 333 x 2 =666.
Example of a high end system with 1600Mhz FSB:
the bus speed is 400Mhz and the ratio of the memory vs CPU is 2:1
(but the gain is limited vs 1:1).