Yeah, RISC-V Is Actually a Good Design

Well known people in the industry such as Dave Jaggar, Jim B. Keller and Dave Ditzel give RISC-V the thumbs up.

TTHE MORE I write about RISC-V the more realize how controversial RISC-V is in many circles. It is not uncommon to see claims that RISC-V is a bad design by RISC zealots trapped in the 1980s. The question is: How much stock should you actually put in random people on the internet making such claims?

Ideally, you should judge a design on its merits, but if that is not good enough for you, then perhaps you can respect the opinions of well-respected microprocessor designers. Here are a few of them making remarks on RISC-V.

Dave Jaggar — Arm Designer

Recently, Dave Jaggar gave a talk on the history of Arm Ltd. and their microprocessors. Who is Dave Jaggar you ask? Here is what wikipedia says:

David Jaggar (born 4 February 1967) is a computer scientist who was responsible for the development of the ARM architecture between 1992 and 2000, redefining it from a low-cost workstation processor to the dominant embedded system processor.

Jaggar did many important designs which contributed to the success of Arm. One essential choice, he was responsible for inventing compressed 16-bit instructions (Thumb) which made Arm a big success within the embedded space. Without Thumb Arm would never have made it into the Smartphone market. Arm got picked by Nokia because they gave dense code, high performance and low-power usage all in one package. That would have been impossible with compressed instructions. Interestingly, modern 64-bit Arm doesn’t have compressed instructions, but it is an important part of RISC-V.

In his talk about Arm history, Dave Jaggar is asked what architecture to look into if you are interested in getting into microprocessors. Jaggar responds (51 minutes in):

Are there any ARM snipers? I would Google RISC-V and find out all about it. They have done a fine instruction-set, a fine job, and they are explaining it. Berkeley and Stanford are behind it. There are obviously commercial companies such as SiFive doing things, but it is the state-of-the-art for 32-bit general purpose…