Geardown mode for odd CAS latency on Ryzen 3000 and how to test stability

[GregI]

I have read on some places like reddit that if I have RAM with a DOCP profile of odd numbers, geardown mode will set them to usually 1 higher to achieve even speeds. The memory has been rated to run 15-15-15-35. The QVL list of my board sated the memory runs at the rated numbers

My question is, for stability sakes if geardown mode does make my timing in the 16 should I just leave it as is? What performance losses/gains will I get from tinkering with geardown via a 3000 series CPU? It's a B450-F if this matters

I obviously want to make sure if my board does run at CAS 15 that it's stable. What's the best program to test this and how ong do I need to run the test for to ensure it's fine?

 

[Murphy]

Geardown mode rounds up all timing parameters to an even number of clock cycles (sauce), as for the performance losses/gains only you can know for certain as there's so many variables involved (timings, motherboard, RAM) it's impossible to compare one system to another or know without testing, however some testing AMD did shows the performance gains/losses are probably not worth bothering about.

As for testing I've been using TM 0.12 made by the same guy who wrote Ryzen DRAM calculator, there's a link to it at the bottom of this article on TPU from 1usmus that talks about memory overclocking and tweaking, it's worth a read from the start IMO.

 

[Smiffy-UK]

Geardown mode rounds up all timing parameters to an even number of clock cycles (sauce), as for the performance losses/gains only you can know for certain as there's so many variables involved (timings, motherboard, RAM) it's impossible to compare one system to another or know without testing, however some testing AMD did shows the performance gains/losses are probably not worth bothering about.

As for testing I've been using TM 0.12 made by the same guy who wrote Ryzen DRAM calculator, there's a link to it at the bottom of this article on TPU from 1usmus that talks about memory overclocking and tweaking, it's worth a read from the start IMO.

That's awesome thanks foe the link.im in the process of tuning my ram this week and this will definitely help me. Thank you.

 

[Murphy]

Yea I'm doing the same that's why i had them, so far my efforts have amounted to discovering i can't beat my BIOS auto settings.

Although to be fair i think i went a bit too far in my first attempt as i used pretty tight timings, got errors, and decided to reset everything to default before trying again. I'm seeing how far i can get the infinity fabric to clock before making another attempt at memory.