MSI x870 Tomahawk EXPO not working

D

derekfoster1971262029b

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Hi all, I recently bought the x870 Tomahawk with Ryzen 9950x and a 64 GB Ram Kit (2x 32gb sticks): Corsair cmk64gx5m2b6000z30. I am on the latest A16 beta bios and whenever I enable the EXPO setting the board fails to boot with A6 motherboard code - the RAM is rated at CL30 6000MHz. I have tried many different settings (EXPO on/off while manually setting 6000Mhz and lower speeds etc.) but nothing works. Also had MCR and Power down off and on but the system will only boot with the RAM at its default 4800 MHz CL40 speeds.
Any suggestions on how to get the RAM working at advertised speeds on this board would be greatly appreciated.
Thanks!
 
Solution
M
expo actually means overclocking

expo ram is "certified" to run at expo profile settings
cpu is "cerfified" to run at amd spec DDR5-5600
mainboards should be able to run the memory as stated in the QVL documentation (if the memory kit is not present in the QVL prepare for surprises)

so if you have problems with expo memory the percentages must be split like this

40% unlucky IMC (or other cpu related problem, mounting pressure for example)
30% unlucky ram kit (sometimes the memory needs a small tweak to run at expo values)
30% unlucky mb (defective memory lanes, very common on ddr5 motherboards, with no vendor exceptions)

this is why support have to answer like that
"in theory" the cpu is more likely to be the problem because...
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wow wow wow, that x870 motherboard doesn't seem to work with DDR5 6000, when it says it should ?
And no better news from MSI than "it's probably your CPU" ?

I was going to buy a x870-p, I actually won't.

Thank you for those infos
 
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expo actually means overclocking

expo ram is "certified" to run at expo profile settings
cpu is "cerfified" to run at amd spec DDR5-5600
mainboards should be able to run the memory as stated in the QVL documentation (if the memory kit is not present in the QVL prepare for surprises)

so if you have problems with expo memory the percentages must be split like this

40% unlucky IMC (or other cpu related problem, mounting pressure for example)
30% unlucky ram kit (sometimes the memory needs a small tweak to run at expo values)
30% unlucky mb (defective memory lanes, very common on ddr5 motherboards, with no vendor exceptions)

this is why support have to answer like that
"in theory" the cpu is more likely to be the problem because you are officially out of its certified operation range.

"in practice", when diagnosing, you should follow a slightly different path:
1) first try 1 dimm at once or better test with another ram kit, with similar specs, prioritizing the correct A2 or A2/B2 slots
2) then reseat the cpu and change the pressure of the heathsink, try the same memory with a different budget/cheaper cpu on the same mb, or test the ram on a different pc if you have access to another working machine
3) after you have removed the ram kit from the equation (1), if you everything else fails or you want to skip step 2, swapping the mb changes so many variables that it's usually resolutive (unless you have a bad cpu of course)
 
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Solution
I have same error code "Ab" with the Corsair CMK32GX5M2B6000Z30 kit, even on latest A17 bios from yesterday. A friend has a different Corsair kit same speed but the RGB version with different memory chips on it and it was running fine, so i bought those instead and will see if it boots on Monday when they arrive. That kit is CMH32GX5M2B6000Z30K and is on the QVL list.
 
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and maybe try to set timings manually : Corsair CL30 6000 factory is 30-36-36-76,
G.Skill is usually 30-40-40-96 or sometimes 30-36-36-96. Maybe you could try all these 3 timings settings, to see if any works
 
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Have this same problem here with CMK32GX5M2B6000Z30 RAM in two separate builds, both cannot post when set to Expo (or XMP), stuck on 4800 tried multiple (including the latest) BIOS versions.

The odd thing is, it's listed as compatible:

1731834067117.png
 
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Hello everyone,

Just to let you know, I also have this motherboard with a 9800X3D.

And like you, I’m encountering issues:

  1. 1)Sometimes, at startup, it tells me that I’ve changed my hardware.

2) I get BSODs when I enable AMD EXPO. I have this RAM:
G.Skill Trident Z5 Neo White RGB - 32 GB (2 x 16 GB) 6000 MHz - CAS 28

  1. 3) I’m also facing the issue of accessing the BIOS, which is very difficult because the screen disconnects every time (I have an RTX 4090).
But the main issue is really the blue screens...
 
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Swapped out the Corsair CMK32GX5M2B6000Z30 (Ab error wouldn't boot) with G.Skill F5-6000J3038F16GX2-TZ5N (both 6000/CL30). Boots fine with Expo enabled, tried rebooting, shutting down etc (some people here had issues doing that), no problems. In windows now running TestMem5, so far so good, no errors.

edit: ran 3 different passes of TestMem5 (each 1+ hour), no issues, no weirdness (yet), fingers crossed :)
 
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I have a very similar issue on R9800X3D+Tomahawk x870 and 48GB (2x24GB) KINGSTON FURY Renegade RGB (CP0000041548034). System only boots when RAM are at 4800, anything above that and it won't boot at all. Expo1 is set to 8000mhz but the RAM speed automatically gets capped at 4800mhz anyway. Looks like a major BIOS update is required...
 
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4800 is default spec speed, I hope they can improve compatibility is clear there is something not working completely right in bios.
 
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New ram kit arrived, replaced CMK32GX5M2B6000Z30 kit with CMH32GX5M2B6000Z30K and it works as expected. I also noticed with the other ones it didnt do the same boot process (by looking at the ezdebug screen) so maybe it is skiping memory training with that kit or something, but looks like it can be fixed in future bios.
 
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marcos.vidal.154a02d1 said:
Un nouveau kit de RAM est arrivé, j'ai remplacé le kit CMK32GX5M2B6000Z30 par le kit CMH32GX5M2B6000Z30K et il fonctionne comme prévu. J'ai également remarqué qu'avec les autres, il n'effectuait pas le même processus de démarrage (en regardant l'écran ezdebug), donc peut-être qu'il saute l'entraînement de la mémoire avec ce kit ou quelque chose comme ça, mais il semble que cela puisse être corrigé dans le futur bios.
Click to expand...
Does it work correctly with AMD Expo enabled?



Thanks for the reference I'm going to have my G-Skill bars replaced by the Corsairs then..
 
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I just tried the new A1A bios released today (Nov 21, 2024). No change for my two ram kits.

Corsair CMK64GX5M2B6000Z30: Does not boot on EXPO. Ab error code
Team Group CTCED532G6000HC30DC01: Boots on EXPO. Memory test throws errors
 
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I can confirm that CMH32GX5M2B6000Z30K is running with EXPO settings, but I have massive problems with the board as explained here: https://forum-en.msi.com/index.php?threads/msi-x870-tomahawk-random-bsod-hypervisor-error.406263/

Onboard HDMI with iGPU has issues too, the screen gets black every view minutes for a few seconds.

I feel like a pre-alpha tester at the moment, on Saturday I can test a new CPU if my current 7700 is defective, if that is the case then I apologize to MSI.
 
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gerhard.kreu159b02e2 said:
I can confirm that CMH32GX5M2B6000Z30K is running with EXPO settings, but I have massive problems with the board as explained here: https://forum-en.msi.com/index.php?threads/msi-x870-tomahawk-random-bsod-hypervisor-error.406263/

Onboard HDMI with iGPU has issues too, the screen gets black every view minutes for a few seconds.

I feel like a pre-alpha tester at the moment, on Saturday I can test a new CPU if my current 7700 is defective, if that is the case then I apologize to MSI.
Click to expand...
Had exacly the same issue with igpu and amd driver.
You need to go to overclocking in bios and set PBO on expert and add positive 30 on GFX curve
This solved the issue with black screen for me
 
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