I consider it completely sufficient if there is any true OSS hardware which is able to run Linux with acceptable performance. Of course big applications like LibreOffice won't make fun on such systems. However we have TeX etc. which runs well even on small systems. I remember writing my own TeX documents on an 8 MHz Atari ST, and it worked well!
I agree with the previous poster: "you don't need a fast processor, just a processor that is fast enough."
If some day we had a small OSS cpu for Linux with acceptable performance which could be implemented in pure SMD like the monster 6502 - that would be nice!
Gaisler would be easier one to implement in ASIC. The Leon4 is a 4-core variant. In any case, the Leon3 and key I.P. are GPL'd specifically for open-source to build on it. SPARC ISA only require $99 fee to use SPARC-compatible line. OSS people just keep ignoring it. Meanwhile, academics have built on it and the Leon3FT variant is often used in space applications.
So, get either booting on a FPGA, install Linux, and have at it. :)
RISC-V is the best open one to get on right now. The ISA is well-designed plus open. There are simulators, high-speed CPU's, compilers, and so on for it. Surprisingly, many big companies are also backing it on top of the academics doing it. There's at least a dozen RISC-V implementations in progress.
Note: OpenRISC is not RISC-V. It was a competing ISA that's fallen to the wayside as RISC-V's popularity soared. It did get used in Milkymist IIRC. Best to ignore it except maybe out of personal curiosity in favor of RISC-V and SPARC.
The main problem with software is web browser these days. You can find niche browser engines that would be somewhat lightweight, but 80% of sites would not work correct with them.
I agree with the previous poster: "you don't need a fast processor, just a processor that is fast enough."
If some day we had a small OSS cpu for Linux with acceptable performance which could be implemented in pure SMD like the monster 6502 - that would be nice!