Andrew Waterman's thesis ("Design of the RISC-V Instruction Set Architecture") has a very approachable comparison of RISC-V to MIPS, SPARC, Alpha, ARMv7, ARMv8,

Andrew Waterman's thesis ("Design of the RISC-V Instruction Set Architecture") has a very approachable comparison of RISC-V to MIPS, SPARC, Alpha, ARMv7, ARMv8, OpenRISC, and x86: https://www2.eecs.berkeley.edu/Pubs/TechRpts/2016/EECS-2016-1.pdf https://www2.eecs.berkeley.edu/Pubs/TechRpts/2016/EECS-2016-...