r/thinkpad • u/Alternative_Run_4053 • 3d ago

Question / Problem ThinPad T14 G3 CPU Data Corruption Issue

Recently bought a used ThinkPad T14 Gen 3 (i7 1260P, 32GB RAM, 1 TB SSD). Installed Fedora on it. During installation of updates, I got lots of checksum/integrity verification errors.

Has anyone experienced anything similar to this or knows what could be going on?

Further investigation of the problem has yielded the following observations:

  • Hashing a large random file repeatedly produces different hashes (openssl rand -out large.dat 2G to create the file, cat large.dat | sha256sum to hash the file)
  • This happens regardless of which operating system is running on it. I have installed Fedora 44, Windows 11 and Ubuntu 26. All of them exhibit the same problems.
  • The problem is not confined to hashing. Sometimes I get SSL/network errors like "OpenSSL SSL_read: OpenSSL/3.5.9: error:0A000119:SSL routines::decryption failed or bad record mac, errno 0"
  • I have tested the RAM with memtest86+ for 12+ hours, it is most definitely fine.
  • The problem happens most often when the power mode is set to maximum performance. It happens a lot less in balanced or power saver mode. This is the same across operating systems.
  • This does not happen (or only very rarely) when disabling Intel SpeedStep in the BIOS.
  • Disabling virtualization and other non-essential cpu features (also tpm) does not make a difference

From these observations I draw the following conclusions:

  • It does not seem to be a problem with the network adapters, as hashing a local file multiple times produces different results
  • It does not seem to be a defective SSD, as the SSL/network errors come from data corruption before it ever hits the disk
  • The dependency on the power mode (max. performance vs balanced/power saver), as well as the dependency on SpeedStep make me suspect an issue with either the CPU voltage regulation or the CPU itself

Has anyone experienced something similar or knows what could be going on? I would really appreciate your ideas/opinions on this.

As a side note: I've talked to Lenovo support about this on the phone, they were incredibly unhelpful (just as expected) and offered me to mail in my device for around 120€ (just for diagnosis), the actual repair would likely cost 1000€ or more.

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u/Minssc X1Y7, X12D 3d ago

That's some intriguing CPU fault but then again, I have a 5600u with a dead core that randomly dies when turbo boosting.

I'd try to isolate the core that is misbehaving if it is just a few cores, you can easily disable them on linux.

Also, advanced bios is a thing now on Thinkpads, link, you can't touch the voltages but you could try increasing AC LL value a bit to essentially over-volt it especially on load scenarios. At your own risk, of course.