EXPO Instability on ROG Strix B650-A with Latest BIOS

[HakanD]

I have been using this system for about 2 months. Before the initial setup, I updated the BIOS to the latest version. Since day one, whenever I enable EXPO at 6000 CL30, sometimes the system fails to POST, or even if it boots, I encounter blue screen errors and system freezes. When I run TestMem5, the system freezes within 20 seconds. I tried many different settings with the latest BIOS versions but couldn't achieve stability. So, I ended up running my RAM at a stable 5600 CL28 instead. Today, I flashed the oldest BIOS available for my Ryzen 7 9700X, version 2613, and so far the system is stable with EXPO enabled at 6000 CL30. I ran a 10-minute TestMem5 session without any errors. Of course, I will test it longer when I have more time. For reference, my RAM kit is listed on the motherboard's official QVL (Qualified Vendor List) for compatibility. I would appreciate it if someone could explain why I can't run 5600+ speeds stably with newer BIOS versions on this system. Thank you.

My system specs: CPU AMD Ryzen 7 9700X, Motherboard ASUS ROG Strix B650-A Gaming WiFi, RAM Corsair Vengeance RGB 32GB (2x16GB) 6000MHz DDR5 CL30 1.40V EXPO/XMP (CMH32GX5M2B6000Z30W), OS Windows 11 Home 24H2. Any help or ideas are welcome.

[Silent_Scone]

Hi @HakanD 

It's a how long is a piece of string question, as it depends where the instability is coming from. AGESA updates can also change stability. On the current BIOS you're using, use Karhu RAM Test to validate OC stability.

https://rog-forum.asus.com/t5/technologies-explained/xmp-amp-expo-memory-stability-methodology-amp-t...

[HakanD]

After BIOS version 2613, no newer BIOS is stable for EXPO. I noticed that on 2613, with Memory Context Restore disabled, the yellow DRAM LED stays on for about 90 seconds before boot. On newer BIOS versions, even with Memory Context Restore disabled, the yellow LED only stays on for about 20 seconds. It seems that memory training is not happening properly anymore, maybe to speed up boot times. This could be the reason for EXPO instability.

[gupsterg]

Buying QVL RAM does not mean you will have stability as CPU IMC will be a factor for stability also. Buying EXPO RAM does not guarantee stability for same reason.

On your CPU and type of RAM kit (ie 2x16GB = 1 dimm per channel, single rank) 5600MT/s is official supported speed, see the 2x1R under connectivity on product page.

I have owned 2x R5 9600X, 1x R7 9700X and 1x R7 9800X3D, used with X670E TUF/HERO, non QVL RAM kits:-

i) Patriot Viper Venom 2x16GB 6200C40 (SK Hynix M die)

ii) Patriot Viper Venom 2x16GB 7000C32 (SK Hynix A die)

iii) Kingbank Dark 2x24GB 6800C32 (SK Hynix M die)

All CPUs reached 6000MT/s with ease, only one of four did not reach 6200MT/s. All did 6000MT/s with around SOC 1.05V to 1.1V, only one CPU needed 1.15V if I recall correctly.

Perhaps share a ZenTimings screenshot and members can comment on what to try to aid stability.

What is DIMM temperature when stress testing with TM5?

Which TM5 profile are you stress testing with?

What FCLK are you using?

[HakanD]

In the attached image, BIOS version 2613 runs stable with only EXPO enabled, but the POST time takes around 90 seconds.
In contrast, BIOS version 2208 (also shown in the image) is unstable with only EXPO enabled — sometimes the PC fails to POST, or if it boots, it freezes during RAM testing, and occasionally I have to reset the BIOS.Currently, I’m using the latest BIOS 3222, and with my 5600 CL28 manual settings, the system is working flawlessly.What I want to highlight is that none of the BIOS versions released after 2613 can run stable at 6000MT/s.
The most noticeable difference is that the POST time is much shorter (around 20 seconds), which makes me think memory training might not be working properly.

[HakanD]

I'm using it like this right now

[gupsterg]

@HakanD 

BIOS contain various firmware updates, CPU Microcode, CPU System Management Unit, CPU Memory controller, etc. In ZenTimings the numbers in brackets are CPU SMU FW version.

At times newer BIOS vs very old BIOS the resistances differ. Flash BIOS 2613, use EXPO and get the settings in use. You can set them manually on a newer BIOS, should get you stability in my opinion.

 Cross reference resistances between ZenTimings and Ryzen Master, just to make sure ZT is reading them correctly.

In ZT > Tools > System Info gets the window I have next to Ryzen Master in my screen shot.

[HakanD]

I will reload 2613 bios and take a visual of these values ​​with expo open, thank you for your help.

[gupsterg · Accepted solution]

@HakanD 

No problem.

Later BIOS should be improved stability, not worse from what I have seen on my setups, so do find it strange what your experiencing. I've purposefully used older BIOS all the way back to July 2024 on my systems just to get experience.

There are other settings that can improve training, reference these screen shots, don't do the Nitro 1 2 1 setup leave those settings [Auto].

HWINFO when opened in Full Mode may show you what RAM IC is in use, if not clearly stated which die version just lower tRFC to identify.

 Far left RAM IC, left of table ns, top of table memory speed, middle of table tRFC values to set in BIOS.

[HakanD]

I replied with this image but I think it was deleted from the forum or I don't know what happened, I am writing again. I did a 15 minute test with expo open testmem5 extreme with 2613 bios and it did not give any error, ram temperature reached a maximum of 50.2 degrees, zentimings cannot read some values ​​with the old 2613 bios.