This has been tapped out many times in different ways already. ETH has developed these and given them over for open source management and commercialization. The have a whole host of research projects around low energy cores and different accelerators.
The idea is to have very competitive core for the 64bit embedded core that is fully open and has lots of ways to combine it with other cores and other accelerators.
This core is cutting edge for a commercial open source embedded 64bit capable chip, but it is not the highest performance core in RISC-V.
Play around with this website to see all the ETH chips, many are RISC-V: http://asic.ethz.ch/
The idea is to have very competitive core for the 64bit embedded core that is fully open and has lots of ways to combine it with other cores and other accelerators.
This core is cutting edge for a commercial open source embedded 64bit capable chip, but it is not the highest performance core in RISC-V.
Play around with this website to see all the ETH chips, many are RISC-V: http://asic.ethz.ch/