no, you don\'t have to overclock the memory in order to use it with that motherboard, like Samwise said.. it just means that you have more potential to have an easier time overclocking than someone with slower memory.
Memory will downclock to whatever your board is capable of running, the thing is, nearly all computer components are capable of actually running faster than they are configured to run stock (memory, FSB on the motherboard, CPU, videocard)
I would return the memory and get slightly cheaper stuff that will run exactly the same as that expensive stuff you bought (at stock settings). It\'s like buying a Ferrari and only driving it the speed limit.. why even buy it then when a honda civic would do just as well for much less?