ASRock TRX40 Creator | AMD TR 3960x | CORSAIR Vengeance LPX 32GB RAM (CMK64GX4M2D3000C16) | 2x EVGA RTX 2080 Super Hybrid | 2x Intel 660p NVMe | 2x Toshiba SATA HDD | Win10x64
TLDR: I can't get memory recognized on slots A1 and A2 of the motherboard and I don't know how to tell if I have a bad mobo or a bad IMC on the CPU. Initially all slots reported RAM but system wasn't stable until it threw a Memory PMU training error after I went from default 2133MHz to 3000MHz (XMP 1) then back to default again.
I have tried multiple sticks of RAM in these slots. All other slots work (and all RAM works in other slots), but with configurations of 2 to 8 DIMMs (all the same RAM from the same batch) A1 and A2 give me "Memory PMU Training error at Socket 0 Channel 2 DIMM 0 & DIMM 1" (when both are occupied) or "Memory PMU Training error at Socket 0 Channel 2 DIMM 1" (when only using slots A2 and B2 per the Memory Configuration page of the motherboard manual for 2 sticks of RAM.
Initially I populated all 8 slots with RAM and benchmarked at 2133MHz. Then when trying to run a SfM benchmark (intended use of this machine) I got an unexpected reboot partway through. Tested the RAM overnight with WMD and came back to a frozen system in windows. Rebooted and event viewer said all the RAM was fine. Loaded XMP profile 1 (3000MHz) and benchmarked great with Passmark (99th percentile, 6778 total, 43468 CPU, 2908 Memory). Tried the SfM benchmark again and got an unexpected reboot partway through again. Reloaded defaults and BIOS finally threw the Memory PMU training error. The system was never stable at 2133MHz or 3000MHz until I got the error and A1 and A2 were disabled. Since they became disabled, I see Memory PMU training error any time a stick is in A1 or A2, and I have never seen any stick of RAM work in them again.
Since BIOS threw the PMU error I haven't had any system freezes or reboots. I can populate all six other slots of the motherboard and run at 3000MHz (XMP profile 1) for days without an issue. Any time I put RAM in A1 or A2, XMP won't stick, BIOS cycles several times, and memory drops to 2133MHz with PMU error (even if only 2 sticks - in A2 and B2). After giving up on this channel (channel 2 apparently?) I gradually filled RAM and tested at 2133MHz and 3000MHz for C2/D2, C1/D1, and finally B1&B2 and with all configurations I am successfully running at XMP profile 1.
Is it possible to test if it's a bad mobo or IMC without swapping out another one of either (or both)?
Seems like that error might indicate faulty RAM MEMORY from googling the error.
3- This link indicates a bad Motherboard since the User installed 3 different RAM Modules on the two non working DIMM Slots and one other User said a bent pin on the CPU caused the issue- https://www.reddit.com/r/buildapc/comments/e9jks6/2_of_my_ram_slots_wont_work/
Of course it could still be a defective Motherboard DIMM slots or controller or CPU.
Try running MEMTEST86 and see if any errors shows up with all RAM Modules installed. Make sure BIOS/UEFI is reset to Factory settings -Default. That should help eliminate defective RAM Modules.
riveryeti, I have this problem and assumed it was the MB, but do not know how to suggest you differentiate. This is a user forum, so I suggest you contact AMD Online Support. They should also be able to tell you if they see many memory controller problems. It is a major pain to swap the MB, but it would be my first try. I have a 3970X with slot C2 problems. I have not tried C1 yet, but will soon. I assume you are running three channel mode. It should run well there - 75% data rate. I will try that if A1 -> D1, don't work. I am too tired to swap my board - would be forth time (3 on 2990WX). My 3970X ran fine for several weeks, then through a fit - crash and memory errors 026 decimal, Severe memory management error. I have a favor to ask: The message I get is close to "PMU Memory Training Error
Socket 0, Channel 3, Dimm 1". Can you post your equivalent error and tell me how you tied it to A1/A2? After some research I decided that PMU is "Power Management Unit" and I think it is code in the BIOS similar to SMU (System Management Unit). I think AMD releases it and MB vendors integrate it into the BIOS. SMU version is revealed by the AIDA64 application, do no know about PMU. Thanks and enjoy, John.
I ruled out defective RAM because I can put 8 different sticks of RAM in A1 or A2 and none of them work, ever. But all of them work, always, if I put them in B1,B2,C1,C2,D1, or D2.
riveryeti, thanks much. Not much correlation there. I was thinking Channel 3 would be C. But if Channel 2 is A, then what the heck? I will look in the BIOS the next time. I'm doing some cleanup work before I start serious debug. I have a Gigabyte TRX40 DESIGNARE and four sticks of 8GB G.Skill B-Dies.
Do you mean the link I supplied did not work? It works fine for me then and now. If it fails for you then please search for "AMD online support". I think it is important for you to talk to AMD. Thanks and enjoy, John.
Good idea to open a ASRock Tech Support Ticket. That way they can decide if you need to RMA your motherboard to be checked and tested for being defective.
You can check the CPU by installing it on another compatible motherboard and see if the same thing occurs. If it doesn't then it is a good indication the motherboard you have is defective.
If you can't test your CPU on another compatible motherboard, then I suggest you open an Online AMD Warranty Request Ticket. That way you can explain the symptoms you are having and AMD can determine if the CPU needs to be RMAed. They may suggest you run certain tests before determining if you need to RMA the CPU.
You can open an Online AMD Warranty Request from here: https://www.amd.com/en/support/kb/warranty-information/rma-form
riveryeti, I have seen this now on three different MBs and three different processors but all TR. RMAing the MB did not help me. I am going to open a support Ticket with AMD. When I get running again, I will try a very slight increase in SOC voltage to see if that helps. I will increase by 10 or 20 milivolts. I just scanned my screenshots and found 2990WX at 1.0 Volts, a 3970X at 1.1 volts. Some other processors were as low as 0.825 volts. If you are interesting in trying this, then check you current value (Ryzen Master) and up it a little. We may need to do this in BIOS to get through boot. If you do try, please let me know the results and I will do the same. Thanks and enjoy, John.
Got the response below from AMD this AM... then called ASRock to see if they have a loaner mobo I could try and they suggested re-seating the CPU after checking for bent pins (which I did before install and installed very carefully), and they said if that still didn't work they'd replace the mobo, but if it still doesn't work, then it's the CPU...
I'm in this weird place where I can't tell if it's the mobo or CPU unless I have another of A or B, which I don't <sigh>.
------------AMD Customer Support email:
riveryeti, it will be a couple days till I can test the SOC voltage boost. Are you willing to try before you dismantle your system? Remember, just 10 or 20 millivolts. Thanks and enjoy, John.