Honestly I’ll just send it back at this point. I have kernel panics that point to at least two of the cores being bad. Which would explain the sporadic nature of the errors. Also why memcheck ran fine because it only uses the first core by default. Too bad I haven’t thought about it when running memtest because it lets you select cores explicitly.

Welp no change. I’m guessing the motherboard firmware already contained the latest microcode. Oh well, was worth a try, thank you.

It’s a pain in the butt to swap CPUs one more time but that may pale in comparison to trying to convince the shop that a core is bad and having intermittent faults. 🤪

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?

BIOS is up to date, CPU model explicitly listed as supported, memtest ran fine, not using XMP profiles.

All hardware is the same, I’m trying to upgrade from a Ryzen 3100 so everything should be compatible. Both old and new CPU have a 65W TDP.

I’m on Manjaro, everything is up to date, kernel is 6.12.17.

Memory runs at 2133 MHz, same as for the other CPU. I usually don’t tweak BIOS much if at all from the default settings, just change the boot drive and stuff like “don’t show full logo at startup”.

I’ve add some voltage readings in the post and answered some other posts here.

Everything is up to date as far as I can tell, I did Windows too.

memtest ran fine for a couple of hours, CPU stress test hang up partway through though, while CPU temp was around 75C.

Yep, it’s explicitly listed in the supported list and BIOS is up to date.

RAM is indeed at 2133 MHz and the cooling is great, got a tower cooler (Scythe Kotetsu mark II), idle temps are in the low 30’s C, stress temp was 76C.

Motherboard is a Gigabyte B450 Aorus M. It’s fully updated and support for this particular CPU is explicitly listed in a past revision of the mobo firmware.

Manual doesn’t list any specific CPU settings but their website says stepping A0, and that’s what the defaults were setting. Also I got “core speed: 400 MHz”, “multiplier: x 4.0 (14-36)”.

even some normal batch cpus might sometimes require a bit more (or less) juice or a system tweak

What does that involve? I wouldn’t know where to begin changing voltages or other parameters. I suspect I shouldn’t just faff about in the BIOS and hope for the best. :/