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cmu16gx4m2a2666c16 overclocking settings


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I purchased x2 kits of cmu16gx4m2a2666c16 which in total supplies my system with 32gb of ram. I purchased this kit because it advertised "Built from a custom performance PCB and highly-screened Memory ICs for superior overclocking potential". I have been able to clock it at its 2666 speed but no higher.


My system is as followed;


Motherboard: Gigabyte GA-AX370-Gaming 5 (rev. 1.0)

CPU: Ryzen 1800x

PSU: Corsair 850x (Corsair carbide 540 case, h110i cooling, and a corsair ssd mounting bracket to hold my nzxt hue+ controller. :))


I checked on the latest version of SIV and it had 2666 as the highest XMP profile and frankly to get it to boot to 2666 (from 2100) I had to use manual timings from the spec sheet of the ram. I've tried higher a voltage 1.35-1.4 to try 2900(iirc) & 3200 but no luck, it wouldn't even post but the computer is stable at 2666 with manual timings.


I am wondering if there are any other timings I can try that are known to work with this ram to achieve a overclock? It was a selling point on the ram for me.



Thanks much,


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The 2666 MHz is the overclock from 2133 and there are no gurantees beyond that. You are probably somewhat fortunate to get it to run two mixed kits at 2666 on a brand new model processor that is still in the early BIOS stages. All you can do is loosen the timings some more. What did you try at 3200? 18-20-20-4x?


Unfortunately, there are no guaranteed timings for a mixed kit trying to run +500 MHz over the specified XMP speed. The correct settings will be unique to your setup and will require a lot of trial and error. I don't have any Ryzen experience, but perhaps someone else has a better handle on its influence on the memory settings.

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Ouch. I should have researched ddr4 vs ddr3 because when I was using ddr3 I had room for overclocking over the speced amount on the ram. The ram advertises that it can be overclocked and I did not think that 2100 or w/e was the normal clocked and it came at 2666 overclocked already. With that being said I would have bought faster ram out the gate. The motherboard said 3000/3200 (overclocked) and the other ram speeds like 2666/2100 with out overclocked next to it. Because of this I figured I'd clock my 2666 to 3000 or 3200 depending. I did not think that I could buy 3200 ram and use it in my motherboard and that I had to overclock 2666 ram to get to 3200/3000. Bah. Perhaps a bios update or two will fix the touchy ram overclocking on my board.


I did try increasing the timings and voltage and the computer shut down on boot, it did not even get to post then the bios reset to default. I haven't tried it since, I'll stick with 2666 for now until another revision or two comes out. If that doesn't fix it I'll sell this ram and go another route.

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Often you can overclock a kit beyond the XMP preset, but how far depends on the individual kit. Most will do a peg or two up, but 3200 is a definite jump from 2666. A batch that can run 3200 probably winds up being sold as 3200 XMP. That may change as the DDR4 format evolves and the top end stretches out further. I do think the mixed kit makes reaching the higher frequencies a much tougher goal.
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I have same cpu like you ,/rm650x / asus strix 1070oc

also I am waiting for my gigabyte gaming k7 motherboard


I have CMD16GX4M2B2400C10 rams which is 2400mhz 1.35v CL10

I would like to use it with higher mhz because i saw some videos (ryzen)giving better performance with higher mhz on rams.


I am planing to do put higher CL on my rams and want to reach 3200 3600mhz


corsaior dominator platinum rams are same at 1.2v 2133mhz same timing.

But in case its hard for you because ur rams are CL16 already

I posted my topic on corsair forum to waiting answer to be my guide



here is the video if you want to watch it.



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Ugh, getting cl16 ram to begin with... I am disappointed to say the least. On two fronts because I did not research it well enough and when I read that "A good overclocker" I thought it meant past 2666... I feel a little misled and a little foolish at the same time. I wish that the advertisement was done a little differently it would have spurned me to research the issue more and I would have spent a little more. I'll probably put these up for sale since I don't want ram just at 2666, I was hoping to get 2900/3000 or whatever.
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