Why would someone use OpenSPARC rather than riscv? Seems like the Linux distros have some a-tier support for riscv64, or will soon. Debian supports SPARC right? Anyone else?

That's not even getting into upstream testing. I imagine there is more development attention to riscv tooling e.g. GCC, llvm, glibc, musl, util-linux, et cetera.

OpenSPARC/POWER is the reason why I am not too excited about RiscV. We have had open GPL designs for close to 20 years and they just sort of went nowhere. RiscV seems to be something neat for those that design processors or work with them low level but for the general person I do not think it will result in anything amazingly different.

SPARC was only open for 32 bit and POWER was not actually open until many years after RISC-V.

> RiscV seems to be something neat for those that design processors or work with them low level but for the general person I do not think it will result in anything amazingly different.

For the general person of course nothing technical matters. But for the industry it matters a whole lot.

SPARC only has a 32bit version that's open. Its really not a option. Even if want to use something 32bit, you would like some upgrade path for the future. And technically its also just worse in pretty much every way. After the standardisation there was very little continued progress and investment.

OpenPOWER only became open many, many years after RISC-V was open. OpenPOWER was basically just a marketing name, it was not actually open. Once RISC-V was opened for real, eventually the pressure was on OpenPOWER to actually be opened.

However by the time they opened it up RISC-V already had all the momentum both commercially and in terms of open development.

OpenSPARC seems to have had open 64-bit designs released before RISC-V was launched?

"In March 2006, the complete design of Sun Microsystems' UltraSPARC T1 microprocessor was released-in open-source form, it was named OpenSPARC T1. In early 2008, its successor, OpenSPARC T2, was also released in open-source form. These were the first (and still only) 64-bit microprocessors ever open-sourced. " -https://www.oracle.com/servers/technologies/opensparc.html

The 32bit is a standard 'IEEE Standard 1754-1994'. The 64 bit implementation was released by SPARC International but its not a standard.

As far as I know without joining SPARC International you are not allowed to commercially use SPARC 64bit commercially.

There might be open implementations, but that doesn't mean you can be sued for using the architecture.