Yes its right how you work out the speed is 200mhz fsb bus speed times the multiplier at 6.5=1300Mhz.
As said its likely you have cool and quiet enabled, you can turn this off in the bios if you hit the del key or F1 key or F2 key when you power the pc on, once in the bios go to the power settings section and it should be in there. Don`t forget to save the settings before you exit the bios.