TIL: The AMD K5 was RISC

AMD K5 CPU

About 28 years ago (?!) I ran a Linux server for a small college. We always had a shoestring budget so our hardware setup was always just a bit non-mainstream. (I also didn’t know what I was doing half the time, so, like, we had a generic NE2000 ISA Ethernet card (something like this) providing connectivity, until I realized how CPU-bound that made network activity; upgrading to a 3Com 3C905 PCI board with bus mastering was amazing.)

I built pretty much all of the systems we used, servers and workstations, and my first Linux box started off as a Pentium 60, before we migrated it to an AMD K5 PR133 on, IIRC, an Intel i430FX chipset. I remember it being a fine performer, especially once we had the network interface card performance figured out.

Today I learned: “The K5 was based upon an internal highly parallel RISC processor architecture with an x86 decoding front-end.” (Wikipedia) Also TIL, AMD made RISC microprocessors, and used their internal design, the Am29000, which provided the basis (“many of the ideas and individual parts of the 29k designs”) for the K5. (Wikipedia) Huh. Cool.

The 1990s were an interesting, awesome time in the computer space, before everything standardized on Intel and compatibles. SPARC, UltraSPARC; MIPS; Power / PowerPC; DEC’s Alpha; HP’s PA-RISC... By 2005, Apple had ditched their PowerPC architecture for Intel chips, and the following years (roughly 2006–2009) saw all of the remaining RISC UNIX workstations pulled from the market (IBM’s IntelliStation Power machines were, IIRC, the last holdout (discontinued in January 2009), though the Power line lives on, at least as of 2024, in servers).

I feel like we’re getting back into Interesting Times, at least a bit. Low end ARM designs are found in the ubiquitous Raspberry Pi boards and embedded Arduinos; Apple Silicon and now Qualcomm’s SnapDragon X have made Advanced RISC Machines (“ARM”) platforms viable for mainstream computing beyond cell phones and tablets; RISC-V is starting to gain some serious traction (e.g., Google Android tools; Framework laptop system board).

Fun times. Oh, and, lest we forget: