What's the oldest CPU you've used with Linux
80386
80486
Pentium
Pentium II / Celeron
Pentium III / Celeron
Pentium 4
Ryzen 1000-3000
MIPS
SPARC
HP PA-RISC
IBM POWER
ARM

seen from United States

seen from Mexico
seen from China
seen from Lithuania

seen from United States
seen from Japan
seen from Germany

seen from Russia

seen from Germany
seen from Germany

seen from China

seen from United States

seen from United States

seen from Singapore

seen from Poland
seen from Germany
seen from Maldives

seen from United States

seen from Maldives
seen from Hong Kong SAR China
What's the oldest CPU you've used with Linux
80386
80486
Pentium
Pentium II / Celeron
Pentium III / Celeron
Pentium 4
Ryzen 1000-3000
MIPS
SPARC
HP PA-RISC
IBM POWER
ARM
HP 9000/C100 graphics workstation (1995)
My C100 is not as nice as the one on Wikipedia, but it’s fully working. The machine was used in a small GIS company as a server for two X terminals (probably HP 700X). It is equipped with 100-MHz PA-7200 CPU, 256 MB of RAM, 2-GB SCSI HDD, two additional 100-Mbit/s network NICs and a single-head version of the HP 8-bit frame-buffer card. The original owners used it with an external SCSI drive for user data and did regular backups using the internal tape drive. They didn’t delete anything from the internal system drive when they stopped using it (the drive has only about 10 megs of free space).
Owners were probably smokers so I had to clean the internals of the machine from the greasy dust. Fortunately, there was no visible corrosion on logic boards. Now it is ready for a fresh installation of the HP-UX operating system including the complete aC++ development environment.
A processor/RAM board from the HP 9000 C100 UNIX workstation. My first contact with PA-RISC...
Discover the future of outdated PA-RISC hardware in the tech world. Will it continue to be used, or is it time to consider newer alternative
HP-UX and Common Desktop Environment (CDE)
The HP-UX installation was successfully finished with a large text over a half of the screen saying “FAILURE!” written in ASCII art. The whole process took about ten hours and after an automatic restart, the system booted up in the graphics environment.
The CDE GUI is not as intuitive as the one on SGI IRIX but I can live with it. I was more surprised that all color schemes (about 20) looked ugly as hell. The guys who were responsible for this were probably on LSD. Otherwise, I cannot understand the color combinations they created.
On the bright side – although the CPU runs only on 100MHz, the overall feeling of speed is better than on 200-MHz SGI O2. I have only a low-end graphics card capable of 1280x1024 in 256 colors (actually it can combine one 256-color palette for an active window and second 256-color palette for the rest), it is very fast and has no problems with refreshing windows while moving.
Btw the system cannot use audio in the CDE until the network is fully configured. It wouldn’t be a true UNIX without such jokes.