Comment 11 for bug 1163587

It is my impression that specifying "mtrr_gran_size/mtrr_chunk_size" when "mtrr_cleanup: can not find optimal value" is still useful on some systems.
The latest system where I helped identifying good values (according to https://github.com/tomreyn/linux_mtrr_size_fix) was a
  Gigabyte Z97X-Gaming 3, BIOS F7 09/18/2015
with
  Intel i5-4690K (incl. GPU)
and
  some dedicated Nvidia graphics chipset
running
  Linux version 5.4.0-40-generic (buildd@lcy01-amd64-011) (gcc version 9.3.0 (Ubuntu 9.3.0-10ubuntu2)) #44-Ubuntu SMP Tue Jun 23 00:01:04 UTC 2020 (Ubuntu 5.4.0-40.44-generic 5.4.44)
and Nvidia proprietary driver 440.100:
https://paste.ubuntu.com/p/VqnhtHmWd4/

Setting specific mtrr_gran_size/mtrr_chunk_size values actually helped the user get reliable graphics on Xorg on this Ubuntu 18.04 (+LTSE stack) system.

So it does still seem relevant at times.