Overclocking DDR4 4266 issue

[Phongski99]

Hi All,



I have a kit of 32gb 4000 16-19-19-39 Gskill, I had them stable for a few days at @4266 16-16-16-34-1 Dram 1.5v /SA-Auto/IO-Auto, have run hours of memory stress runs and gaming stress with no errors or crashes.

Yesterday I turned on the PC and was unable to boot @ 4266 16-16-16-34-1 continuous memory training loop this corrected itself when I adjusted to 16-17-17-34.

Any reason or solutions to get them to train back to cas 16, is it also ideal to have the SA/IO voltages to auto or have them fixed and what would be the ideal voltage to set them at

11900k @5.2 Maximus apex 13
Timings used below with the exception of TCKE being 6 and CR 1

Thank you in advanced

 

[Woomack]

In general, it's hard to set 2x16GB at 4266 16-16-16 1.50V. As long as the IC is good then it still usually needs a higher voltage or more relaxed timings. My 4400 kit likes 16-17-17 at 4266 and I can push it some more but requires a higher voltage or has some stability issues during longer work. I run it in a small ITX PC and after some tests, I noticed that some additional sensors are showing significantly lower temps when RAM runs at more relaxed timings but lower voltages so I run it at 4400 18-18-18 1.40V even though the XMP is 17-18-18 1.50V. At first, I wanted CL16 but the required voltages (also additional) were causing some overheating and stability issues while the performance was about the same.

I was thinking to get 4266 CL16-19-19 but I found 4400 17-18-18 which is the highest frequency dual-rank Samsung B kit on the market and cost me as much as the 4266 kit. I'm not sure what is the real difference between IC in these kits but new series are generally sold as 4000/4266 16-19-19 and at least 2x8GB kits that I tested, required tRCD/tRP 1 higher than CL at DDR4-4600+ while older kits were running well at CL=tRCD/tRP. Maybe some coincidence, maybe just a different batch of B-die.

I will only add that my 4400 kit hits a wall at 4400. It literally doesn't boot at 4533 while runs fine at 4400 or can go down to CL14/15 for tests. You can also notice that all these kits are sold at 1.50V in the XMP. There is a reason for that. Simply some IC won't even boot at 4000+ and less than 1.45V. The Team Group 2x16GB 3600 kit that I had some time ago needed 1.45V only to boot at 4000+, regardless of timings, so the same voltage for CL15, 16, 17, or 18.
For tighter main timings or stabilizing 16-16-16, you may need 1.55V+. At this point, I would check something like 15-16-16 as it may work at not much higher voltage.

 

[Phongski99]

Thanks Woomack, I was going to Pm you directly before posting this but figured I have been annoying you enough with my other questions LOL.

Yep thanks for the explanation I will settle on more relaxed timings as suggested

 

[EarthDog]

Good idea to post questions in public so all can see...

 

[Woomack]

My favorite are emails from people who aren't active on the forums, block private messages, and expect that I will reply

 

[EarthDog]

Any I get, I ask to post in public. Good for the forums too.

 

[dejo]

You could always load defaults and start fresh with your settings. If you have changed the UEFI, that could also force you to change timings.


Although I dont post much- we do need to keep viewable traffic up.