Discussion Only one core is visible in Linux - Ryzen 5 2600 (if you can boot at all)

[marcus0]

Hello guys and gals!

I'm brand new on the forum. I haven't registered before, because I was able to solve my previous issues by searching existing threads.
Until now.

Symptoms:
-Can't boot the computer with Windows, even from bootable USB that works with other computer: it freezes about 3 seconds after the boot process starts and the keyboard powers off (num lock doesn't work, keyboard illumination is gone)
-Only way that I can boot is with Linux, and only by adding the kernel parameter spec_store_bypass_disable=off, and even then I can only see one CPU core via hardinfo, lscpu and cat /proc/cpuinfo with a Ryzen 5 2600
If I don't pass the parameter than booting stops either with a "do_IRQ: 1.55 No irq handler for vector" or a kernel panic at _raw_spin_lock, tried with several different USB bootable recovery tools.
-When I start memtest and set it to round robin between CPU cores, it freezes (!)
My goals:
I don't know whether the CPU or the motherboard is the culprit. I don't want to buy both, but I'm fairly certain one of those is causing the problem. Could you help me find out?

Further context:
-RAM and CPU was overclocked via UEFI with more than adequate cooling for about 2 years. When the PC was first powered on after a day that it had no power (switch on the power socket was turned off) it had minor troubles starting: it powered off a couple seconds after I turned it on, then automatically turned on back again, but I've checked the UEFI settings and the overclocking weren't set back to default. This was fairly regular in the past.
-I've used Windows previously, but one day it just failed to boot. Recovery didn't boot either, but it did show the repair screen at boot. It just froze during the early stage of booting. Power off was the only thing that helped. That's when I've tried to boot from USB the first time.
-Had to update BIOS to version 1.10 to 4.60 (https://www.asrock.com/mb/AMD/B450M Pro4/index.asp#BIOS) just to get this far: before that the gparted USB stick froze at the boot menu (normally it counts down from 30, it stopped at 30, keyboard & num lock not responding, no keyboard illumination/power)
-Tried different keyboard, didn't help
-Reseated & repasted CPU, reseated disks, GPU
-I've done a full memtest with the default multi-core settings (just F2 after it starts) and it passed

Hardware info:
Ryzen 5 2600
Asrock B450M Pro4
2x8 GB RAM
USB keyboard, backlit
BitFenix Formula Gold 550W
1xHDD SATA3
2xM.2 SSD
Nvidia GTX 1080
CPU temperature: 42-49 Celsius, didn't get higher with "stress --cpu 8".

 

[sdifox]

Memtest? Have you tried it at stock settings? Reseat ram?


Actually do you have a spare psu you can try?

 

[marcus0]

Thank you for your reply!
I've reseated the RAM, and now memtest freezes right on the first test. Tried it with different - even with the one that worked before-, and it always freezes, keyboard is not responding (num lock doesn't work, (c)onfiguration button does nothing). Tried it with different configurations, i.e. only one memory stick, switched the slots, nothing helped so far.
As for your other question, sadly no, I don't have a spare PSU :S

 

[VirtualLarry]

Without actually diagnosing it, I would suggest that possibly your CPU / memory-controller is toasted from 2 years of OC'ing.

 

[marcus0]

Thank you for your answer! You're probably right, I just don't know which one to buy: CPU or mobo
RAM: 2x8GB 3000 MHz G.Skill Aegis kit
I still have the old settings in the UEFI:
From the base DDR4-2133 1.2 V to DDR4-3000 1.35V

 

[sdifox]

Have you tried to set everything back to stock, ie reset the bios?

 

[marcus0]

Yes, after I've updated it to 4.60 I've left everything on default, except for the boot settings. Tried it with UEFI secure but enabled and disabled, too.

 

[sdifox]

Have you tried taking off cpu cooler and reapply thermal conduction grease?

Why is your SSBD on in the first place?

 

[marcus0]

Yes, I have. Rebooted and tried to boot Windows from USB several times since then, still no change.
I think it would be best to get it to a professional, who has replacement parts and try to replace the cpu, then the motherboard and see which one is faulty.

 

[sdifox]

Yes, I have. Rebooted and tried to boot Windows from USB several times since then, still no change.
I think it would be best to get it to a professional, who has replacement parts and try to replace the cpu, then the motherboard and see which one is faulty.

depending on labour cost where you are I guess.

 

[marcus0]

AFAIK SSBD is on by default, based on this:
https://www.kernel.org/doc/html/latest/admin-guide/kernel-parameters.html

 

[marcus0]

I've dropped it off at a PC repair shop, so it's out of my hands now.
Thank you both for taking the time to read & reply! I'll keep you posted with the final "verdict"

 

[marcus0]

Replaced the motherboard and the CPU both and now it works.
Thank you for taking the time to read and reply, have a nice day!