Looking at the Intel E3-1230v2 CPU, under Memory types it says "DDR3-1333/1600". My question is, in what way does the CPU limit the RAM speed? What would happen if I put in a DDR3-2133 RAM chip together with the CPU, if the motherboard supports the faster RAM speed? Would it be better to get a RAM chip that is DDR3-1600 so it matches the CPU's listed frequency?

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    The CPU can only access the memory at the speed it was designed to do so at. The memory can only be access as quickly as it was designed. If you use faster memory then the CPU supoprts the speed is limited by the CPU. You gain nothing by putting memory faster then can be supported by the motherboard, infact, past a certain point the memory might not even result in a POST.
    – Ramhound
    May 14 '14 at 18:16
  • @Ramhound: Would it be better to get a RAM chip that is DDR3-1600 so it matches the CPU's listed frequency or is there no significant difference?
    – Claudiu
    May 14 '14 at 18:18
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    It makes no difference. If the RAM run as a faster frequency then supported by the CPU it will be ran at the frequency that is supported. The simple fact is your unlikely to see a difference unless you double or triple the difference of difference memory. This means that 1600 mhz and 1800 mhz while in theory one is faster you really won't see a performance difference. You would only see a difference in benchmarking which only provides a general overview of your potential performance.
    – Ramhound
    May 14 '14 at 18:21

The RAM will be downclocked to match the FSB/Memory controller speeds. In this case that’d be 1600Mhz. So buying the faster rated memory is a waste of money unless you plan to change the CPU soon enough.

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    It's not always a waste of money. For example, memory rated for 2133 MHz at 1.65V would likely be able to run at 1600 MHz at a lower voltage, decreasing power usage and heat generated, and potentially increasing system stability. If this matters to you, or if the price difference is small, it could be worth getting the faster memory. But for most users this will not be significant.
    – user55325
    May 14 '14 at 20:00
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    True, but I doubt the OP is the kind to be overclocking/undervolting if he's asking about about clocks like this. At least it'll be very stable if nothing is changed.
    – Linef4ult
    May 14 '14 at 20:07
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    Certainly, but the information might be helpful to anyone else who finds the question.
    – user55325
    May 14 '14 at 20:09
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    Better RAM might also be cheaper (I'm assuming because of lower demand or higher availability). For example right now I can buy 2x8GB 1333MHZ CL9 RAM for Apple Laptops for EUR 106.50 or the same with 1600MHZ CL11 RAM for EUR 102.00 from Amazon Germany from the same reseller.
    – qubodup
    Sep 27 '15 at 19:13
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    Does it have any effect with on-board integrating graphics? None mentioned about it.
    – dh16
    May 11 '16 at 15:14

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