nonsense. rocket-chip has been taped out at 45nm and achieved 1.5ghz, years ago. india's shakti core is going into 20nm and as a 6-stage pipeline will run at 2.5ghz. as that one uses only 120mW, even 16 2.5ghz cores would only consume around 3 watts (!!!).

caveat of course: the L1/L2 cache power consumption isn't included in that figure, but, crucially, with the Compressed Instructions reducing cache misses by 20-25% that's equivalent to having approximately double the I-cache size.

basically by a fresh start they're on to a winner.

Maybe a Pentium IV then? I don't think RISC-V -- or any processor really -- gets taken seriously in the desktop/laptop space unless it can compete with one of Intel's earlier chips.

Unlikely that anyone will even try to target desktop/laptop market with a RISC-V CPU, it is a very established market without much future growth. The plays will be in embedded devices, especially areas which requires pheripherals with tight integration with the CPU, this is where an open and extensible ISA can be a significant benefit. Examples today are controllers inside SSDs/SDcards. In future maybe also microcontrollers with integrated machine/deep learning co-processors.