DDR3-1866 not supported by CPU

[SandyB]

I have begun a new build. I bought a quad memory kit: 4x4gb G.Skill Ripjaws X DDR3-1866 F3-14900 CL9Q - 16GBXL for my ASRock X79 Extreme 6 motherboard, then read that my i7-3820 processor only supports DDR3-1600. Another tech forum said that this motherboard will automatically clock the RAM down to 1600 and I will never notice the difference. Is this so? Or should I just return DDR3-1866 and get the 1600?

[parsec]

Intel does spec the i7-3820 CPU for up to DDR3 1600 memory. That is the speed they guarantee will work with this CPU.

But, as with the majority of Intel CPUs released in the past several years, it will work fine with faster memory. I have never heard of an Intel CPU that did not work with memory that is faster than the CPUs spec. The spec is very conservative, and people use faster memory with them all the time.

The only limitation you will really have is what your mother board's spec is for the memory it can use. I'm sure it is more than 1600, and likely over 2000, so 1866 is fine.

It is important that the memory you use is listed on your boards list of qualified memory, even if the manufacture states the product will work with X79/i7-3xxx CPUs. Most new boards are very picky about which memory they will use, and if your memory is not on the list and does not work, that is not unusual.

The difference in performance between 1600 and 1866 memory in real world usage is very small, or none at all. If your 1866 memory cost much more than 1600 memory, I would get the 1600, since you'll never notice any difference.

[CRRacer]

I have that same memory, and while I am using it in a Z77 extreme4 mother board and running it at 1866, if you got a good price on it, I'd keep it.

If I recall correctly, I had to use a XMP profile in the UEFI to set the memory to 1866, otherwise it booted up as 1600. BTW, if you needed to, you can slit that memory up and in to two PC's and run it as 8GB per PC in dual channel (it's only going to be dual channel no matter if you install 2 or 4 sticks anyway).