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Overclocking RAM&timmings for new Zen3


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I am new to the Ryzen world and we have seen in the SYN_Vander tests that we can extract some extra "free" fps tweaking the RAM. At the momment there is no juice in OC the CPU.

This OC process was described a bit by Fenris in this post in another thread.

I would like to use this thread to compile the theoretical steps and expand them, just to share it , ask questions about that and most important determine if it is worth the effort. It is a tedious process.


1) You first need to check with Taiphoon Burner what kind of DIEs you got (http://www.softnology.biz/files.html) and save that to an XML file, 

2) Use Ryzen DRAM calculator, (https://www.techpowerup.com/download/ryzen-dram-calculator/) and  import that XML, press"safe settings" to get some lead on primaries and secondary timings, as well as research how much voltage you can put in.  Samsung B-Dies easily manage 1.45V to 1.5V continuously, and can be clocked highly with tight timings.

3) Take a picture with your mobile of the timmings and then introduce them to the BIOS.

4) Pray to see if your PC boot again. If not, Reset the CMOS jumper.


It's not trivial and there are quite a few guides floating around, best to plan a full day to get through it if you haven't done it yet. A few tips:

1) Don't use Ryzen Master. It doesn't work all the time. Use your BIOS.

2) Don't watch too many YouTubers. Most of them just fake knowledge, and failed irl. (Except Igorslab and der8auer ❤️ )

3) Don't follow someone else's settings blindly, your RAM is in SKU#x and was built in week y and the humidity was z. 

4) You absolutely must use the latest BIOS available, which should be ending with .151 and maybe a beta flag (as of end of November 2020).

5) If you OC it too hard, it won't post. Best to put the PC's Reset switch to your "delete CMOS" jumper if the system won't post: then you can pull the plug, hold down the button for 15 seconds, and start the rig back up with reset BIOS. 

6) Every time you test a new OC setting, save it. Also keep a stable setting saved to return to in save spot 1. The MSI bios will ask you to load a BIOS after a CMOS reset: you can load the stable one with Alt-F1 then (you'll see).

7) change things incrementally. 

😎 last but not least: Do run stability tests over night- so not skip them, by all means! Memtest86, the one in dram calculator, and more are available. Aida64 is fine too. Make sure to read out your Window's event log for WHEA errors/events. 

This is explained in this video https://www.youtube.com/watch?v=Bwr7sl5eZUM



In theory, the best performance is obtained when FCLK=UCLK=MCLK




My question are:

1) If last version of DRAM calculator is from May-2020, are those timmings also valid for Zen3 CPUs?

2) Reading this, it seems that first at all one need to know what is the maximum FCLK achivable by his CPU. So the timmings thing (if worth) should came after that.

3) If I try to reset the CMOS in the power supply cable unplug it doesn´t work. But plugged but with PC off, it works.


Also, I have bought a new 4x8Gb kit of 3800MHz with CL14. This is F4-3800C14Q-32GTZN.  

My Mobo Gigabyte Aorus Pro is not in the QVL but it works at 3800 CL14. But the problem is with the FCLK and UCKL. They are not 1900.

I am using latest official BIOS F12b from Gygabyte. 

Is there and easy way to change the FCLK and UCLK frequencies?







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Your lnfinity fabric can't sustain 1900 Mhz, so it automatically drops to half memory rate. 

  Maybe you could get it there with some tweaks, but looks like with this bios and settings your IF can't do 1900Mhz.

  Some Zen3 cpus can do 2000Mhz, but nothing above 1800 is certain. 

 Zen 2 was even worse. I remember that "Silicon Lotery" company, that sold binned CPUs, found out that only about twelve percent of the 3950x cpus they got, could run 1900Mhz infinity fabric.

 Mine does 1833Mhz max.

Amd said they will bring improvements to the AGESA firmware, in january, to help with the infinity fabric stability, but we'll see. 

Edited by Jaws2002
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I have returned the 4x8Gb kit of 3800MHz with CL14 (F4-3800C14Q-32GTZN for 450€) and put again my previous RAM 2x16Gb 3600-CL16 (F4-3600C16D-32GTZR for 271€).


I did the following tests with the Benchmark:


CPU test v4.505 with 2x8 3800CL14 xmp profile (MCLK=1900, FCLK=1800, UCLK=950)
Frames: 6632 - Time: 60000ms - Avg: 110.533 - Min: 97 - Max: 147
Frames: 6806 - Time: 60000ms - Avg: 113.433 - Min: 98 - Max: 159
Frames: 6714 - Time: 60000ms - Avg: 111.900 - Min: 93 - Max: 155


CPU test v4.505 with 4x8 3800CL14 xmp profile (MCLK=1900, FCLK=1800, UCLK=950)
Frames: 6768 - Time: 60000ms - Avg: 112.800 - Min: 98 - Max: 152
Frames: 6978 - Time: 60000ms - Avg: 116.300 - Min: 101 - Max: 155
Frames: 6853 - Time: 60000ms - Avg: 114.217 - Min: 101 - Max: 151


So, there is an small influence of 2x8 vs 4x8. So Dual rank helps a little bit. Unforntunately I still have not skills to practice with FCLK and timings.


CPU test v4.505b with 2x16 3600CL16 xmp profile (MCLK=1800, FCLK=1800, UCLK=1800)
Frames: 7108 - Time: 60000ms - Avg: 118.467 - Min: 103 - Max: 158
Frames: 7220 - Time: 60000ms - Avg: 120.333 - Min: 106 - Max: 166
Frames: 7051 - Time: 60000ms - Avg: 117.517 - Min: 103 - Max: 152


Just with default XMP profile I had MCLK=FCLK=UCLK. Perhaps in future I could try to go to 1833, 1866 and perhaps 1900. And most importantly, measure the gain in IL-2.

Or if someone with knowledge (and time) can run the CPU test with default XMP profile versus optimized timings, then it would be great. :blush:

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