For example, my Asrock P67 Extreme4 says this:

  • Supports DDR3 2133(OC)/1866(OC)/1600/1333/1066 non-ECC, un-buffered memory

Is RAM clocked at 2400 MHz compatible? Will the performance be downgraded or it just won't work?

I found other questions but they were related to the CPU cap at 1600 MHz. This cap is related to the motherboard, specs says 2133(OC) max.

  • @zyboxenterprises You need to read before coming here assuming things. The link you posted say: "The motherboard RAM frequency support is 2400(OC)/1600/1333/1066". That motherboard supports OC 2400mhz, so RAM at 2400mhz will work. That question is about to OC the mobo to match the 2400mhz that the RAM offers. My question is clear, my mobo doesn't support 2400mhz, the speed of the RAM im asking. Plus the voltage thing. Jul 2, 2014 at 17:46
  • Yes, but as I said before, the information can easily be found on the internet. It is also a common illusion that you have to match the RAM up to your motherboard; in fact, almost any RAM will work, as long as you match the RAM type (ECC, non-ECC, DDR3, DDR2, etc).
    – AStopher
    Jul 2, 2014 at 18:13
  • Sure, you can find it easily, but the link you posted here trying to prove it, it's totally wrong. You just messed things up. Good, you talk about reputation, how mature you are. "mine is bigger". Jul 2, 2014 at 22:09

1 Answer 1


The RAM would down-clock automatically to DDR3-2133 speed and it would run fine. This is safe and will only make you lose the speed edge of the faster module.

If there are more than one and they are different: The RAM in your system will 1. all run at the same speed, and 2. run at the lowest supported speed by any one stick of installed RAM. Different sticks of RAM can NOT run at different speeds in the same system. The motherboard will make both RAM modules runs in the lower speed.

  • 1
    The RAM would down clock only if it had that capability. Much easier to purchase known support memory then purchasing memory that might not work. I recall a question on this very website about memory that refused to work, it was slightly different, because the memory required 0.15v more then the motherboard supported.
    – Ramhound
    Jul 2, 2014 at 11:30
  • 1
    I agree with your comment, it is better to purchase the proper one and the voltage can be an issue. However I think clock is set by motherboard, I mean RAM just operates (somehow) on what it gets as a clock doesn't choose on what clock it works or support. Jul 2, 2014 at 12:10
  • Memory has some circuitry to support technolgies like XMP
    – Ramhound
    Jul 2, 2014 at 12:21
  • 1
    All XMP does is allow your BIOS to automatically configure the overclocked DRAM voltage and timing information instead of forcing you to do it manually. It does not guarantee stability. You can use XMP RAM in non-XMP motherboards and you can use non-XMP RAM in XMP motherboards. In both cases you will simply have to set the timings and voltage manually if you decide to go outside of the recommended specifications. Jul 2, 2014 at 12:39
  • I am more then aware of that fact.
    – Ramhound
    Jul 2, 2014 at 12:50

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