1866 memory clocked at 1333 on sabertooth 990x

mcopinger,

I'm an overclocking newbie myself, but I think that I can help you out. Just please take what I say with a grain of salt. I wouldn't be saying it if I didn't think I was correct, but my limited experience can't be taken as authoritative.

As I understand it, companies like Corsair make all of the RAM of a specific type on the same factory line. Then they test each stick to see how well it was made (which is affected by how well the chemicals diffused into the metal and such). Then, based on the rating, they package it and sell it as working at a certain speed. Better sticks tend to be packaged as working at a higher speed. If you're really lucky, you may get RAM that can work at a much higher speed than it's packaged for, in which case you can overclock beyond the specification.

Many motherboards have a default of 1333MHz. Your RAM, assuming that it's compatible, may well work at a higher speed, but that's all Corsair is certifying: that it WILL work at a higher speed WHEN you overclock it. Since the speed isn't built into the stick you have to set it when you mess with your BIOS.

Further you should know that your default bus speed (I may be using the wrong term here) is about 133.33MHz. You double that to get the base rated speed, 266.66MHz. And then your RAM's speed is some multiple of that base rated speed (i.e., 5*266.66MHz is 1333MHz, 7*266.66MHz is 1866MHz).

If you had your CPU overclocked, the bus speed may've been changed. Assuming that you left your RAM alone, then the RAM's new speed should be its old multiplier times the NEW bus speed. And if your new bus speed can't be multiplied by an integer to get 1866MHz, then you won't be able to overclock your RAM to 1866MHz (but you can probably still get just a little above or below it).

Finally you should know that overclocking both the CPU and the RAM at the same time is a more difficult task than overclocking either alone. I'm personally having trouble with it, which I was doing before I started typing this reply. Though again, I'm a newbie too.