Quite often, memory that is "rated" by the distributor at over 800MHz (DDR) still only meets the JEDEC
standard for 400MHz (800MHz DDR).
However - memory sold at, say, 1,000MHz DDR sometimes has an EPP
"registration" of the said frequency. So even if the motherboard's BIOS doesn't detect and set the memory to the distributor's rating (and instead sets it to the manufacturer's JEDEC rating), an EPP rating can state timings/subtimings and voltages required for the memory to run at the given frequency. You can usually view the JEDEC and EPP settings by using the program CPU-Z and viewing the "Memory" or "SPD" information tab.
Even if the memory doesn't have JEDEC or EPP registrations at the distributors stated frequency, it is still supposed
to run at the advertised frequency (and/or timings and voltage). It is sometimes just a matter of changing them to actually run at those settings in the BIOS.Edited by Choggs396 - 5/28/08 at 7:49am