Hardware: 9950x, X870E Asrock Taichi Lite, Teamgroup Tcreate 2 x 96gb 6800 CL36-46-46-84 1.4V CTCWD596G6800HC36DDC01, PNY 5080
This represents many hours spent reading reddit, overclock.net, YT and some other sources, then testing, failing, adjusting, over and over. I feel that there is some performance left on the table. Maybe that is for you to pick up where I left off, or maybe I will mess with this again some other time. I will try to credit the threads and individuals that helped. I'm not an expert at overclocking, if that encourages others to do a similar project.
My use case? Not that crazy, just an entrepreneur who wants to run trade apps, CADCAM, video editing, rendering, learn about LLM, and … play games. Maybe all at the same time?
This is a water loop setup with air cooled ram sticks. All stress testing was done with the AC on in the room, probably about 20C ambient. I used y-crunch and LinpackXtreme for shorter tests to see if longer tests were worthwhile. Also, I found memtest86+ booted from a USB helpful to establish settings that would at least boot into WIndows. Also, keep in mind that this is a new build, and so there isn't yet valuable data that could get corrupted during the process.
I think for what we pay for hardware like this, we should expect great results. There are good reasons why dual channel can't run 4 dimms as fast as 2 dimms, but with relatively nice hardware, shouldn't we expect a certain level of performance?
Temperatures: with a 20C ambient and 40mm fans, memory was kept to below 40C
Results: passed 10 cycles of Testmem5 Absolut (32 hours), 24 hours of Prime95, running at 6000mt/s CL30. The Latency is Aida64 60.2 in safe mode, 62 in normal windows11. OCCT latency 79. Write/Read/Copy for Aida64 b/w is 80/85/75 gb/s.
Story time:
At the beginning, this had no trouble posting at 3600. However, I initially had a lot of trouble trying to increase that value. After messing with some timings, even 4200 seemed like a victory. But I know a good deal more this week than I did last week. After some failure and reading, I feel that one thing that may have helped was some of the system settings:
-MCLK=UCLK, Gear Down Mode enabled (sorry)
-OC Tweaker may override settings elsewhere in the UEFI, so timings and bus settings should be set to AUTO, and I worked primarily out of AMD CBS and AMD overclocking menus
-soc/uncore oc mode enabled
-manually setting TDP/PPT/TDC/EDC for 9950x cpu, 170/230/260/225 maybe this helps the IMC? PBO is enabled, but all other CPU settings were AUTO for this process
-Nitro to 1/3/1
-Memory OC mode enable, I choose the 6800expo profile. I believe this automatically sets a few things that work, this may be very specific to this setup. It didn't seem to work as well with this disabled. This possibly needed to be done prior to manual settings.
-Memory context restore and power down mode disabled for this process, let it train.
Timings notes:
You can see that MOST of the 2nd/3rd timings come from "safe/optimal" settings on "Fool-Proof…Guide…" so thank you u/Lysander_au_Lune
when setting tRFC, I noticed that less didn't seem to improve much, and didn't have consistent bench results, so I settled on what you see. tREFI possibly would be fine at 65536, but I set it to 57344 in hopes that it would grant some more stability.
One mistake: for some reason I had tRDRDSC and tWRWRSC very high. It cut the write bandwidth in half! That took me a while to figure out. Stupid, that should be 1.
Primary: lots of trial and error that maybe you can skip. But finally, I went to the 6800 expo settings, validated, then reduced from there. I wanted to see a CL30 based on u/franticbronchitis comment in my initial post on this.
Impedances:
I ran these very specific impedances, inspired by those seen in the YT video below by Game Tech Reviews. Pull Downs where set to AUTO. variation from these numbers didn't seem to work.
FCLK: 2133 seemed to be my speed, less or more didn't seem stable or didn't improve things.
Conclusion:
Criticism is welcome, particularly if you have any requests or comments about stability testing, or performance improvements. For example, maybe it could run faster at 5600 CL28? I'm here to learn and share information.
I don't expect memory or IMC degradation, because my voltages don't seem extreme at all, and thermals stayed quite nice.
This was a lot of work over a three or four weeks. I hope this helps you spend less time.
Once again, thanks to all experts and non-experts alike that helped me get this running by sharing information out on the internet. The only credit I get is for the hours I put in on this, lol, so if someone deserves a shoutout, let me know.
References:
Fool-Proof DDR5 Overclocking Guide for AM5 (Focus on 64GB, Dual Rank)
https://www.reddit.com/r/overclocking/s/v7mhQwWOxZ this is pretty sound, although everything isn't "one size fits all". I needed to run much higher tRFC, for example.
This thread encouraged me to decrease VDDQ and VDDIO to 1.34V, and I believe that helped. VDD is at 1.44V, slightly less or more didn't seem to work.
9950X with 192GB (4x48GB) at EXPO 6000cl30 STABLE
https://www.reddit.com/r/overclocking/s/GWW5iGl6zm
There was a lot of useful info on overclock.net
some of the bus configuration was influenced by this video:
https://youtu.be/q0YtOVZNHiI?si=XIT_titg6tRCoX2s, Game Tech Reviews
This info could be very useful, but it is hard to understand how this stuff works!
https://youtu.be/sDxkous2Ua4?si=WD4pj-jtoBh4BkYk Buildzoid
but this is very cool as well:
https://youtu.be/7J7X7aZvMXQ?si=2cPMGSj3dqR1ZUIR
This was a lot of work over a three or four weeks. I hope this helps you spend less time.
Once again, thanks to all experts and non-experts alike that helped me get this running by sharing information out on the internet. The only credit I get is for the hours I put in on this, lol, so if someone deserves a shoutout, let me know.
3 Comments
I’m confused my 192gb 4dimm kit it running at 6000 cl30 on expo. with no tweaking.
I dont really understand this post, its massive and like whats the point? I have 192GB running 100% stable on its EXPO profile, 6000 Mhz CL30. 9950X3D. No tweaking no BS, it just works. I think some of you are making this way harder than it needs to be.
Great job, and very impressive!
And kudos to AsRock for a great board layout.