I’m trying a new CPU in my PC (Ryzen 5500GT) and I’m seeing:

  • Sporadic kernel panics during boot.
  • Random .ko.zst module files (different one each boot) complaining that ZST decompression failed checksum.
  • Random .so’s failing to find a symbol and causing programs to crash/fail to start.
  • Started a stress-ng sequential session at 5s per stressor and it hung up after a dozen stressors. Couldn’t ctrl-c it and also ps didn’t work anymore. 😅

Funny thing is, other than that the system runs fine (when it boots, that is).

Switched back to my old CPU (that’s the only change in the machine) and all of these things stopped.

That CPU that’s doing that is defective, correct? Just double-checking I’m not missing anything else.

I’ve reset BIOS between CPU swaps and left it at defaults. Could default settings cause a CPU to act like this?

Edit: cooling is good, all temps (chipset, CPU etc.) are in the 30’s C in idle, CPU went up to 75C when stressed. Have a tower cooler (Scythe Kotetsu) with a 120mm fan.

I’m also adding some voltage readings I took from sensors while the problematic CPU was installed:

Vcore: 840mV
+3.3V: 3.31V
+12.0V: 12.10V
+5.0V: 5.01V
VSOC: 780mV
VDDP: 900mV
DRAM: 1.21V
3VSB: 3.29V
VBAT: 3.26V
  • @FauxLiving
    5•6 hours ago

    75C is fine, the CPU will throttle in order to avoid max temps. This isn’t something that should cause instability.

    It’s POSSIBLE that this is a bug that’s fixed with a microcode update, see here for installing it: https://wiki.archlinux.org/title/Microcode

    TL;DR:

    1. Install amd-ucode
    2. Edit /etc/mkinitcpio.conf, add microcode after autodetect
    3. sudo mkinitcpio -P
    4. reboot

    If that doesn’t fix it, and it crashes in Windows too, it may be a hardware problem. There isn’t much you need to do in order to get a CPU working.

    • lemmyvoreOPEnglish
      3•3 hours ago

      This sounds like my best shot, thank you.

      I’ve installed the amd-ucode package. It already adds microcode to the HOOKS array in /etc/mkinitcpio.conf and runs mkinitcpio -P but I’ve moved microcode before autodetect so it bundles code for all CPUs not just for the current one (to have it ready when I swap) and re-ran mkinitcpio -P. Also had to re-run grub-mkconfig -o /boot/grub/grub.cfg.

      I’ve seen the message “Early uncompressed CPIO image generation successful” pass by, and lsinitcpio --early /boot/initramfs-6.12-x86_64.img|grep micro shows kernel/x86/microcode/AuthenticAMD.bin, there’s a /boot/amd-ucode.img, and an initrd parameter for it in grub.cfg. I’ve also confirmed that /usr/lib/firmware/amd-ucode/README lists an update for that new CPU (and for the current one, speaking of which).

      Now from what I understand all I have to do is reboot and the early stage will apply the update?

      Any idea what it looks like when it applies the microcode? Will it appear in dmesg after boot or is it something that happens too early in the boot process?

      • @FauxLiving
        2•3 hours ago

        Yup, just reboot to apply it.

        It’ll show up in dmesg: "microcode updated early to Rev. ###’ etc