Motherboard and RAM clock speed?

Question

Say i have a mobo: that supports DDR3 2200/1333/1066/800 MHz memory modules, and i have some DDR3 @ 1600MHz. What clock speed will the RAM run at? Will it run at 1333 Mhz?

Answer 1

Memory clock speed is dependent on the CPU, not the motherboard. Most current CPUs are 1333MHz FSB. Your motherboard will "read" the SPD off of the CPU and set the FSB automatically to default to the normal "spec" of the CPU.



Because newer memory controllers (on the CPU) can handle different memory frequencies, it is possible to "over clock" memory.



I never encourage it at all. I have dabbled in it a little and I can see no benefit in it. I bechmarked games with memory at 1333MHZ and at 1600MHZ and there was no difference in frame rate.



Overclocking memory is hard on the CPU as well, Running a higher frequency at max volts through a memory controller seems like an awful lot of punishment to the CPU for little to no gains in performance.



ADD:

You are exactally right - an Intel i7 950 FSB runs at 1066MHz stock and your motherboard should default to that speed.

Answer 2

Motherboard Clock Speed

Answer 3

It will run at whatever speed you configure it to run at.



You may have to overclock or underclock your CPU to get it to run at DDR3-1600 speeds. Generally, the reason a motherboard would support 1333 and 2200 but not 1600 is because it doesn't have the right multiplier. But you can use the 1333 multiplier and then overclock until the memory is at 1600.



Likely, it will default to 1333, but that will also depend on what voltage the stick runs on, whether your motherboard supports EPP (or similar thing like SLI memory), and several other factors.