RAM not fully being identified on launch

Littledc · 2025-08-14 16:06:45

So, Ive been using arch for about a month now, and I am having this strange issue where my pc boots with 6gbs of my 64 gigs of ram (2x32) available. I am so lost as to why this is happening, its purely random whether when I get into arch that the system will read all 64 gigs or only 6gigs of ram, and I'm unsure if its an issue with my Motherboard (Albeit I'm pretty sure it isn't), or arch on boot. I am hesitant to think its the hardware only because I would assume that, if the motherboard cant see all the ram, it would boot loop or retrain memory every boot that this issue occurs. This is also keeping in mind that, its not just ignoring a stick its ignoring a large part of memory that, I genuinely cannot tell how its getting to that number. I have not tried to memtest the memory just yet, mostly due to using my pc, but I was wondering if anyone here might have seen this before and maybe if its an issue with boot that can be solved with changing some on boot settings, like hard setting ram memory. Looking for the issue elsewhere has come up with nothing like my issue. Genuinely unsure what is going on. I also have reinstalled GRUB (Updating my BIOS), and that also has not fixed the issue.

For Mobo and RAM specs, its the Asrock X870E taichi and Gskill TridentZ5 neo rgb, ddr5-6000, with an 9950x3d CPU.

Last edited by Littledc (2025-08-14 16:12:30)

seth · 2025-08-14 19:52:40

Post the output of

dmidecode

for either scenario.
And please also post your complete system journal for good and bad boots

sudo journalctl -b -1 | curl -F 'file=@-' 0x0.st

will upload the journal of the previous (-1) boot, you can skip the curl pipe and look around in the journal to identify the condition of the boot.

Littledc · 2025-08-17 04:15:36

With this being an infrequent bug, it might take a while for me to get back with when the ram not loading happens. Ive been trying to get it to reoccur and still have not gotten it to work, oddly. Usually it only takes 3-4 restarts but now all the sudden its not wanting to happen, even though I changed nothing. Either bad odds or really unlucky.
I do at least have the dmidecode output for now of the fully loaded scenario, I will have to keep trying for it to reappear and hopefully get the output for that scenario as well. https://0x0.st/KrYM.txt

Last edited by Littledc (2025-08-17 04:16:23)

seth · 2025-08-17 07:20:01

Usually it only takes 3-4 restarts but now all the sudden its not wanting to happen, even though I changed nothing.

Interim kernel/firmware/microcode update? Drastic environmental changes (temperature/humidity)?

Either bad odds or really unlucky.

Or bugs are just scared of me

Littledc · 2025-08-18 01:04:23

seth wrote:

Interim kernel/firmware/microcode update? Drastic environmental changes (temperature/humidity)?

Maybe, I did do a system update right before the last incident though, so unless they just happened to fix it within the past 2 days, no clue. I hate the intermittent and not easily repeatable bugs. Environment has mostly been the same, so that should not be a factor here.

Or bugs are just scared of me cool

Haha, not the first time Ive had bugs magically vanish upon actually trying to fix them.

Last edited by Littledc (2025-08-18 01:05:08)

ewaller · 2025-08-18 01:41:58

Littledc wrote:

Haha, not the first time Ive had bugs magically vanish upon actually trying to fix them.

Clearly a corner case of Heisenberg's uncertainty principal

Littledc · 2025-08-24 18:20:42

OK! I got the bug to reoccur, here's the outputs:
dmidecode:https://0x0.st/K-zl.txt

journalctrl:https://0x0.st/K-zU.txt

seth · 2025-08-24 19:05:35

Aug 24 12:30:03 littlepc kernel: Memory: 63248632K/64575840K available (19852K kernel code, 2942K rwdata, 16648K rodata, 4664K init, 4952K bss, 1288244K reserved, 0K cma-reserved)

That's 63,248632 GB of 64,57584 GB but the dmidecode is fucked up

        Size: 2 GB
        Form Factor: DIMM
        Set: None
        Locator: DIMM 1
        Bank Locator: P0 CHANNEL A
        Type: DDR5
        Type Detail: Synchronous Unbuffered (Unregistered)
        Speed: 4800 MT/s
        Manufacturer: Unknown
        Serial Number: 00206200
--------
        Size: 2 GB
        Form Factor: DIMM
        Set: None
        Locator: DIMM 1
        Bank Locator: P0 CHANNEL B
        Type: DDR5
        Type Detail: Synchronous Unbuffered (Unregistered)
        Speed: 4800 MT/s
        Manufacturer: Unknown
        Serial Number: 00206200

and lists two 2GB DIMMs
Wrong journal?

From the dmidecode I'd look at the HW config, the bogus size and manufacturer suggest the DIMM doesn't correctly report - 4800MT/s is the DDR5 minimum - are you really running at this speed?
(Typically I'd assume the RAM is overclocked - too much)

Littledc · 2025-08-24 22:43:27

That might explain where its coming up with the ram amount (around 3 GBs, actually, with 1 unavailable for what I assume is reserved and not shown on system monitor)

Ill check the BIOS, I do believe I have the auto boost setting turned on, maybe something is up with that.

Update: Checked the bios, still set to the 4800MT/s, the bios also fully identifies the ram. The Dmidecode when running properly still does not identify the manufacturer, but sees everything else correctly. I will mention that the recreation did happen after doing a system update, perhaps that could be a cause? Ill keep this in mind when I do it again if this actually is a significant step in why this is happening

Last edited by Littledc (2025-08-24 22:53:52)

seth · 2025-08-25 07:48:40

What "recreation"?
Can you post the journal of the boot where you were actually facing the low RAM situation?

sudo journalctl | grep 'littlepc kernel: Memory:'

will hopefully show you a deviating line indicating the date where this happened what will help you to identify the relevant boot.

TooOldForDeInterwebz · 2025-08-25 11:29:16

Could it be something as simple as the RAM not being seated correctly and or profile (which not only changes timings but also increases voltage) not being loaded in UEFI settings?

Littledc · 2025-08-25 13:50:18

seth wrote:

What "recreation"?
Can you post the journal of the boot where you were actually facing the low RAM situation?
sudo journalctl | grep 'littlepc kernel: Memory:'
will hopefully show you a deviating line indicating the date where this happened what will help you to identify the relevant boot.

https://0x0.st/K-IZ.txt

Recreation just being making the bug reappear, sorry for my poor english skills lmao, never was great in english class as a kid even with it being my native tongue.

TooOldForDeInterwebz wrote:

Could it be something as simple as the RAM not being seated correctly and or profile (which not only changes timings but also increases voltage) not being loaded in UEFI settings?

I thought this too, this is my 6th pc build, so this isn't my first rodeo with uncooperative hardware. Reseating did not fix anything though. If it is a hardware issue, my only assumption is that maybe it could be a CPU issue if this is outside of the OS as an issue, specifically on the driver side of things (this is assuming the RAM is not faulty somehow), but idk how possible that is (Haven't taken any ECE classes to know whats going on there, only CS ones)

Last edited by Littledc (2025-08-25 13:55:56)

seth · 2025-08-25 17:51:32

Las time you ran into this was

Aug 24 12:25:40 littlepc kernel: Memory: 2961804K/3234144K available (19852K kernel code, 2942K rwdata, 16648K rodata, 4664K init, 4952K bss, 237608K reserved, 0K cma-reserved)

Should™ be

sudo journalctl -b -4

(depending on whether you've rebooted since this afternoon)

Arch Linux

#1 2025-08-14 16:06:45

RAM not fully being identified on launch

#2 2025-08-14 19:52:40

Re: RAM not fully being identified on launch

#3 2025-08-17 04:15:36

Re: RAM not fully being identified on launch

#4 2025-08-17 07:20:01

Re: RAM not fully being identified on launch

#5 2025-08-18 01:04:23

Re: RAM not fully being identified on launch

#6 2025-08-18 01:41:58

Re: RAM not fully being identified on launch

#7 2025-08-24 18:20:42

Re: RAM not fully being identified on launch

#8 2025-08-24 19:05:35

Re: RAM not fully being identified on launch

#9 2025-08-24 22:43:27

Re: RAM not fully being identified on launch

#10 2025-08-25 07:48:40

Re: RAM not fully being identified on launch

#11 2025-08-25 11:29:16

Re: RAM not fully being identified on launch

#12 2025-08-25 13:50:18

Re: RAM not fully being identified on launch

#13 2025-08-25 17:51:32

Re: RAM not fully being identified on launch

Board footer