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October 20, 2010

Movers and Shakers in HPC: John Gustafson

by Caroline Connor

This is the first in a series of columns on movers and shakers in HPC, written by our newest contributing editor, Caroline Connor.

I had the pleasure of working with John Gustafson when he was Chief Technology Officer for ClearSpeed in 2007. Sure, I had heard about John, known for his work in HPC, describing the notion of weak scaling (Gustafson’s Law), introducing the first commercial computer cluster, winning the first Gordon Bell Award and all that. What surprised me was that there was so much more to John than the public persona. Here is a guy who is a former trampoline gymnast, built his own harpsichords at age 16, and grows orchids in his spare time. All of this is not lost upon me while I sit poolside at John’s lovely home, wondering what else I might uncover as I pull out my recorder.

HPCwire: John, you’re known for your “Reevaluating Amdahl’s Law” paper. Have you ever met Gene Amdahl? Is there any kind of debate still going on between the two of you?

John: (Laughs) I’ve met Gene, and have lunch with him every now and then; he lives right here in the Bay Area. We get along great. No, there’s no debate whatsoever. I’ve asked him things about his “law” that have been bothering me for years, and confirmed that he never meant his 1967 talk to be used to stop progress in parallel processing the way it has. He was debating Slotnick about the architecture of what would become the ILLIAC IV, saying that if you have one instruction stream, then the operating system part of that instruction stream will kill the parallelism. Gene told me that with modern systems, where every processor has its own instruction control, that argument doesn’t apply at all. So no, there’s no rivalry. I admire the man immensely and am honored to have any association with him.

HPCwire: So, what is behind your fascination with historical computers, like the 1939 Atanasoff-Berry Computer that you helped to reconstruct? It seems odd that a guy who works at the leading edge of supercomputing also works on machines that are a trillion times slower.

John: The technology of the era isn’t the important part; it’s what you do with it. So each generation rediscovers clever “tricks” about using tubes, discrete transistors, bit-slice logic, VLSI… and gives it a new name without realizing that there are many giants whose shoulders they could stand on. Another part of it is that Atanasoff has not received the credit he deserves for inventing electronic digital computing. Reconstructing his machine helped to set the record straight, and proved to people that his computer really worked.

HPCwire: I heard that you recently started managing Intel’s Ubiquitous High Performance Computing project for DARPA. What can you tell us about your new role and the project?

John: Well, this is my third time managing a grand “let’s build a big computer” project for DARPA. The first was when Steve Squires was leading the charge at DARPA in the 1980s, which led to the early hypercube projects and eventually to commodity clusters. The second was at Sun Microsystems when DARPA’s Bob Graybill was refocusing everyone on productivity instead of raw specs, and his HPCS program did a lot to realign people with the issues that really matter to computer users. Now, it’s the UHPC program. The goal is to produce an exaflop, or an exa-op, with less than 20 megawatts of electricity. If anyone can get the power efficiency that high in a general-purpose computer, it’s Intel. The aspect most interesting to me is the software part of the challenge. How much are we going to expose the architecture to the compiler developers and the library designers, versus the scientists and engineers who simply want to use the system to get work done? And do people have any idea about how power-hungry and numerically shaky our current “double precision” arithmetic will be when you’re doing a quintillion operations per second? I don’t think they do. So being able to direct such an effort is nothing less than fascinating. Finding time for outside activities just got a whole lot harder!

HPCwire: Speaking of which, what are your favorite hobbies, sports and other interests?

John: Oh, my. I didn’t expect that one. I was once a gymnast and pretty good on the trampoline, but that was quite a while ago. These days I spend my spare time playing piano and harpsichord. I actually learned to snow ski for the first time last year, and I plan on skiing more this season. Other than that, I usually enjoy the great California weather by swimming and hiking. At this point after taking on my new responsibilities for Intel, I feel lucky just to get outdoors enough to get some Vitamin D.

HPCwire: So, how old were you when you first started experimenting with electronics?

John: Oh my god, you would ask this. I don’t know whether to be embarrassed or proud about it, but I was six years old when I was assembling radio transmitters. I entered one in the science fair when I was in first grade, and won. What a geek I was! I saved up for a helium-neon laser and managed to get one when I was fifteen. I had indulgent parents who let me take over three rooms in the basement to make holograms, perform dubious chemical experiments, and generally do the kind of thing you might see in the Amateur Scientist column of Scientific American. By the time I entered Caltech as a freshman, I probably had about a thousand hours of hands-on lab experience, so the chemistry and physics courses seemed pretty easy.

My parents weren’t just indulgent, they were excellent guides. My mother had been an electronics technician at Collins Radio, now Collins-Rockwell, and my father was a chemical engineer turned MD, both as the result of World War II. One of my earliest memories was being taught about the polarity of batteries and electrolytic capacitors by my mother while trying to figure out what wasn’t working on the Heathkit breadboard circuit I just assembled. How geeky is that?

HPCwire: What are two or three interesting things about you that relatively few (or none) of your colleagues or friends know?

John: (Laughs) Well, my grandfather’s first cousin was Greta Garbo. Most of the family who came over from Sweden simply dropped the extra “s” in Gustafsson, but she probably followed someone’s good advice that even ‘Gustafson’ wouldn’t make it in Hollywood and changed her last name completely. Like my grandfather, she was from a poor farm on the outskirts of Stockholm.

Another thing people don’t know is that my father was the first guy to introduce computers into private hospitals in the US. People back then couldn’t figure out what possible use a computer could have in a hospital, but he persisted and said it could plan the diets of everyone, grade their psychological tests, maybe even monitor their electrocardiograms automatically. That was 1961 and 1962. When he visited IBM, I asked if I could go along. So here I was, this seven year old, touring one of the IBM sites in New York, slack-jawed at signs that said things like “Danger: Laser Light”… well, that was where they were working on the very first laser printers. I couldn’t understand why the reel-to-reel tape players kept starting and stopping; I thought they must all have been broken, and I wondered why no one could get them to work properly.

HPCwire: Just out of curiosity, why did you join ClearSpeed a few years ago? Based on your own personal experience, can you share any insights as to why some companies struggle in the HPC market place and so few survive?

John: Thomas Sterling told me once, “I figured out why you joined ClearSpeed: You’re re-living your youth.” I laughed, and knew exactly what he meant. I actually started my career at Floating Point Systems, a company that turned general-purpose computers into compute-intensive workhorses by adding special hardware for high FLOPS rates. I smiled when I got a pitch from ClearSpeed, who thought they’d invented the idea of using accelerators to plug into general-purpose boxes. I said, “So, your target markets are chemistry, structural analysis, and improving LINPACK scores, right?” To which they replied, amazed, “Yeah, how did you know that?” A few weeks later, I was offered the role of CTO and I agreed. It was a lot of fun while it lasted.

Seriously, in my personal opinion, HPC companies usually fail because they don’t identify their customers and their customer needs very accurately. Seymour Cray didn’t make that mistake; he was brilliant at knowing his customer base and what they wanted and needed.

HPCwire: I read just recently that Massively Parallel Technologies has announced a new software environment. As former CEO, can you share some of the history with us?

John: DARPA introduced me to MPT during the HPCS program, saying they had some very innovative ideas worth looking into. Gene Amdahl is on their technical advisory board, so I knew I should take them seriously. I was asked to take the reins to get them better connected to the mainstream HPC community, which I did. MPT has a technology for parallel programming that overlaps communication so well it allows scaling to millions of processors. The latest announcement is about something quite different. They’ve created a way to build programs that looks like the Apps Store, but hierarchical. Sort of the antithesis of open source; you get financial reward for every improvement you can make in a software supply chain. I would probably still be there had Intel not recruited me to direct their Santa Clara research lab in 2009. It was an offer I simply could not resist.

HPCwire: How would you describe yourself to someone who has never met you before, or knows nothing of your background?

John: Whew. That’s hard to do. I’d say that I’m an odd mixture of technophile and extrovert. I love public speaking, meeting people and talking to customers, which I notice isn’t true for a lot of scientist-engineer types. So I guess I’d say, “I’m a research scientist with a right brain.”

HPCwire: Lastly, what do you consider your greatest personal achievement?

John: Being influential in the adoption of parallel processing as a mainstream approach. Until 1988, when I wrote the paper about reevaluating Amdahl’s law, parallel processing was simply an academic curiosity that was viewed somewhat derisively by the big computer companies. When my team at Sandia — thank you, Gary Montry and Bob Benner — demonstrated that you could really get huge speedups on huge numbers of processors, it finally got people to change their minds. I am still amused by people out there gnashing their teeth about how to get performance out of multicore chips. Depending on what school they went to, they might think Amdahl proved that parallel processing will never work, or on the other hand, they might have read my paper and now have a different perception of how we use bigger computers to solve bigger problems, and not to solve the problems that fit existing computers. If that’s what I wind up being remembered for, I have no complaints.

About the Author

An avid HPC watcher and established technology marketing professional; Caroline resides in the California Bay Area and recently joined the HPCwire team as a contributing editor. You can reach her at

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