i7-7700k and Asus Prime Z270-A. 2133MHz vs 2400MHz RAM?

Kilobyte Kid

i7-7700k and Asus Prime Z270-A. 2133MHz vs 2400MHz RAM?

Hi! I'm looking to buy a a kit of two 16GB sticks of Crucial RAM (Ballistix Sport/Tactical/Elite) for my new computer, but I'm totally lost as to what speed I should buy. I have absolutely no experience in overclocking, so I was looking at 2133 MHz or 2400 MHz. But while the documentation for the Z270 chipset says the officially supported speeds are 2133 and 2400, the specs for my motherboard says "2400 MHz (O.C.) / 2133 MHz". I suppose the "(O.C.)" means overclocked? Would that mean that if I bought a kit of 2400's, it would automatically be downclocked to 2133 (without me actively going into the BIOS and adjusting the speed that is..), defeating the purpose of buying 2400 RAM in the first place?


Basically, I would like to get the fastest RAM (and with reasonably low CAS values) I can without having to overclock. The reason for that is that I need a very stable system for studio recording and audio editing, and I'm afraid overclocking might increase the risk of instability. Or am I wrong? Someone mentioned that 2666 MHz is ideal for a combination of speed and stability, does that make sense?


Or maybe the difference between 2133/2400 and higher wouldn't be very noticable for DAW work? The PC would not be used for gaming, but big sample libraries can take a big toll on the RAM, so I figured the RAM speed would be important as well but I don't know.


I've checked for compatibility with my motherboard and all Ballistix series are listed. Any recommendations?



2 Replies
Community Manager

Re: i7-7700k and Asus Prime Z270-A. 2133MHz vs 2400MHz RAM?

Hello Datamaskin,


Thank you for your message and also for considering Crucial for your upgrade.


All of the memory we list against a system is guaranteed to be compatible.  This means if you have looked up the model, all the parts listed there would work perfectly.


I know in your comments you provided the chip set but can you confirm the make and model of the motherboard?  This will be the best way for me to check and see what memory is compatible for you.  


Once I know the model, I can provide you with a link to the fastest memory available for your model.  If you do have any other questions at all, please don't hesitate to ask.

Junket, Crucial Moderator UK
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Kilobyte Kid

Re: i7-7700k and Asus Prime Z270-A. 2133MHz vs 2400MHz RAM?

Thanks for your reply!


My motherboard is the Prime Z270-A. I'm planning to get a kit of Crucial RAM sticks, but after looking through the list of compatible RAM I ended up with more questions than answers. So I'd be very grateful for some guidance in relation to the questions I posted - regarding the 2133 versus 2400 MHz compatibility for my motherboard, if you would recommend me to get some faster RAM and try overclocking the RAM a bit, and if the RAM would still run just as stable as a non-overclocked kit.


Also, my question about whether a kit of 2400 MHz RAM would automatically be downclocked to the highest speed that the motherboard supports (if I didn't actively change the settings in the BIOS or using XMP to overclock). And how (or if) there is a difference in what maximum RAM speed the motherboard supports vs the chipset/processor (which according to Intel is 2400 MHz).


I read somewhere that 2666 MHz RAM is the sweet spot these days, giving the most bang for the buck. Would you agree with that?


Lastly, I wonder if I bought a Crucial RAM kit rated at 3000 MHz or 3200 MHz and downclocked to 2666 MHz or even 2133 MHz, would I get better CAS latency timings?


Thank you! :-)