The intel specification for socket lg 1366 processors is 1333mhz memory. However as with all motherboards the manufacturers of these motherboards over engineer thier boards in order that they can accept higher memory speeds. They are competing with each other if you like. Your memory will have an intel x.m.p (extreme memory profile). At default, as with all memory on the lg 1366 platform it will run at 1333mhz. Once x.m.p has been enabled it will run at 1600mhz in your case.
Was just reading through this post, how would you disable xmp. I'm new to computers and anything to do with over clocking etc in fact I'm most likely the at the pre-beginner stage
Was thing about getting 12GB KINGSTON HYPER-X TRI-DDR3 1600MHz along with an i7 990x CPU and 2 GTX 580's.
The speed at which the RAM runs is determined by two things - the maximum speed of the RAM and the motherboard's settings. What Maestro is saying is that the default settings of the motherboard will run the RAM at 1333MHz and that you can change those settings if you have RAM capable of higher speeds.
The RAM is designed to "tell" the motherboard what settings to use. One of those settings is especially designed for these very fast RAM - those settings are called XMP. By changing a single setting on the motherboard, you tell it to get those XMP settings directly from the RAM - basically it just saves you having to manually set dozns of values.
The reason that these motherboards default to using 1333MHz is that they have to synchronise all of the components to make sure that when one part sends data, another is ready to receive it and not busy doing something else. In order to keep all those timings right and make it easy for us mere mortals to understand, the motherboard presents us with a few values and multipliers - values that we can change that affect all of the main components at the same time. The default values and multipliers mean that the board expects to see 1333MHz RAM. It's easy to change that - to tell the board to use faster or slower RAM - upto a point. The motherboards that PCS uses can easily handle the faster, 1600MHz RAM simply by changing a single setting thanks to XMP.
XMP is not something you'd really need or want to disable - it would just slow your computer down for absolutely no benefit. If you do decide to switch it off, you should read your user manual but even then, I'd suggest you don't even think about changing BIOS settings until you've learned a bit more as you can easily make your PC unstable or unable to boot and some BIOS settings - voltages in particular - can destroy your CPU or other components if set the wrong values.