from 35 different countries. They have
already accomplished amazing things,
and they represent every school in the
university, from law and business to engineering and the social sciences. Given
the gigantic leadership problems that
we have around the world, hopefully
we can get a new generation of young
people out there that are determined to
do better.
John, you’re also writing a book about
leadership.
JOHN: It is at the publisher now. It’s a
short book—it’s meant to be readable
on a cross-country flight. It’s about my
experiences with a variety of leadership
issues and what I learned about it. The
first chapter is humility.
Anything else?
DAVE: With the ending of Dennard
Scaling and Moore’s Law, we must
change the instruction set for major
gains in cost, performance, energy, or
security. Freeing architects from the
chains of proprietary instruction sets
may spur innovation like in the 1980s.
Hence the title of our Turing Lecture: “A
New Golden Age for Computer Architecture: Domain Specific Hardware/Soft-ware Co-Design, Enhanced Security,
Open Instruction Sets, and Agile Chip
Development.”
Leah Hoffmann is a technology writer based in Piermont,
NY, USA.
© 2018 ACM 0001-0782/18/6 $15.00
kinds of functions that these machines
need to do well.
DAVID: The reason that John and I are
such good co-authors is that we have
almost identical world views. Domain-specific architectures are in the newest
chapter of our book, and for sure they’re
an exciting development.
There are two other things I’m interested in. First is RISC-V, an open
instruction set architecture that’s
based on RISC principles. Not too
many people get to work on proprietary instruction sets like ARM and
x86, but everybody can get involved in
the instruction set evolution of RISC-V. The other thing is getting better
at security. So far, we haven’t asked
much of computer hardware in security. I think architects need to step up
and really help attack this problem.
What’s exciting about the RISC-V is
that you can download a full viable
software stack, prototype your idea using an FPGA, stick it on the Internet,
let people attack it, and see whether or
not it works. The iteration loop can be
days instead of the years it takes with
proprietary instruction sets.
John, you’re also involved with the
Knight-Hennessy Scholars Program,
which aims to “build a multidisciplinary community of Stanford graduate students dedicated to finding creative solutions to the world’s greatest
challenges.”
JOHN: We just admitted our first class
coming this fall. We have 49 students
all smartphones and mobile devices.
JOHN: The key thing to understand
is the efficiency issue. When Dave and
I were developing RISC architectures,
we had to find efficient ways to use the
silicon that was available at the time to
get the highest-performance machines.
Today, you’re constrained by a whole
set of different factors. Sometimes it’s
a question of the silicon area, because
you’ve got to be able to sell processors
for a dollar. But the other big constraint
is energy efficiency, because so many
things are battery powered, or you can’t
include a fan to cool them. So the RISC’s
underlying efficiency has enabled it to
catapult into this critical role.
DAVID: It’s kind of like “Back to The
Future.” When they’re selling things
for pennies, people care a lot about the
number of transistors they use. At the
very high end, the instruction set matters less because there are so many other things going on. At the low end, you
even worry about how many registers
you have. What’s nice about RISC is that
it works fine at the high end, and it’s a
big asset at the low end, and that’s why
it’s been so successful.
What excites you both in the field of
computer architecture?
JOHN: As conventional uniprocessors
stall out, there’s a focus now on what
Dave and I have called domain-specific
architectures—architectures that are
designed for specific classes of problems. The obvious example now is deep
neural networks; they use very specific
computing strategies, and you can get
an order of magnitude in efficiency by
designing an architecture that does the
David A. Patterson
“What’s nice about
RISC is that it works
fine at the high end,
and it’s a big asset
at the low end,
and that’s why it’s
been so successful.”