ISC, which will be held in Hamburg for the first time in the 24-year history of the conference, has a well-established reputation for presenting well-founded, precise and up-to-date information in an environment that encourages informal conversations and sharing of ideas. And of all the thought-provoking sessions scheduled for ISC'09, none are likely to spark more discussion than the keynote addresses.

In his presentation, Andy von Bechtolsheim will discuss trends in the high performance computation market, including the challenge of building large fabrics and the role of InfiniBand and 10 Gigabit Ethernet. He will also look at how to address the challenges of building, integrating, and using petascale systems including system power and cooling, system stability, and scalability. Finally, he will look at the impact of solid state memory for HPC deployments and how it can address data bandwidth within the system to deliver improved overall performance through a more balanced system architecture.

Andy Von Bechtolsheim was a co-founder and Chief System Architect at Sun Microsystems, responsible for next generation server, storage, and network architectures. From 1995-96, he was CEO and President of Granite Systems, a Gigabit Ethernet Switching startup company he founded that Cisco acquired in September 1996. From 1996 to 2003, he was VP Engineering and later General Manager for the Gigabit Systems Business Unit at Cisco System that developed the Catalyst 4000/4500 Gigabit Switch family, the highest volume modular switching platform in the industry.

Andy Von Bechtolsheim earned a M.S. in Computer Engineering from Carnegie Mellon University in 1976. He was a doctoral student in Computer Science and Electrical Engineering at Stanford University from 1977-82. He has been honoured with a Fulbright scholarship, a German National Merit Foundation scholarship, the Stanford Entrepreneur Company of the year award, the Smithsonian Leadership Award for Innovation, and is a member of the National Academy of Engineering.

The following interview with Andy von Bechtolsheim by Christoph Poeppe from Spektrum der Wissenschaft - the German sister publication of Scientific American- was translated by Jon Bashor and Heike Walther.

Spektrum der Wissenschaft: What drives a person, who was apparently meant to pursue a scientific career, to take a path that leads him to such exceptional commercial success? What went wrong?

Andreas von Bechtolsheim:I don't see any fundamental conflict between science and commercial success, at least not where I work - in Silicon Valley. All in all, though, I have always been much less interested in academic research and much more interested in how to build better products that drive a commercial success.

Q: But didn't you start out as a physicist?

A:Not really. In 1974, I did win the German Science Fair in Physics building a device that could precisely measure flows using ultrasound, and in high school I took advanced classes in physics and

bio-chemistry, because these were the most interesting classes that were offered. But I was always much more interested in computers and computer science, which is really an engineering discipline. There have been very few major breakthroughs in mathematics and theory in the last twenty-five years that affected the field of computer science. All the new advances that we have seen were really based on better engineering.

Innovation in the computer field is very different than innovating in a traditional industry such as chemistry. At the moment, "Green Energy" is a big focus for venture capitalists. But to make ethanol at a lower cost, you need an unbelievably large amount of investment capital to build new facility, and this is difficult to come by these days.

In information technology, many of the most successful new companies were started with very modest capital. For example Google, which has become the most successful search company, was financed with just 30 million dollars of venture capital. And Google has been branching out to offer all kinds of new services and applications.

Q: I'm really only familiar with Google as a search engine...

A:Besides the Google search engine, there is also Google Maps and Google Apps and Google Talk and the YouTube video portal - the possibilities stretch out from there. The end user just needs a browser and an Internet connection to use all these services. The computer work is done inside Google's gigantic data centres, where with clever engineering and large scale, Google has achieved enormous cost advantages compared to conventional data centres.

Q: How so?

A:Google has built a reliable system environment out of a large number of simple, low-cost servers. Google builds its data centres in locations that have low-cost power and cooling, and it manages these data centre with very few people. It is estimated that the cost per CPU hour in a Google data centre is between one-fifth to one-tenth of a traditional enterprise data centre.

Q: What's your personal connection to Google?

A:My friend David Cheriton, who is a professor at Stanford, introduced me to Sergey Brin and Larry Page. Their idea to sort search results by relevance, which is calculated by the number of links between websites, convinced me right away. It does not matter what the content of a website is, the only thing that counts is how many and how many relevant websites are linked to this website. This approach is immune against tricks some sites use to artificially raise their hits, such as embedding the same word many, many times in a way that is invisible to the user.

And the business model of linking relevant search results to relevant sponsored links was a stroke of genius that had not occurred to anyone else.

Q: In your new company, Arista, you are focused mainly on building network switches. What pushed you in this direction?

A:All large web companies are building large data centres for what is now called "Cloud computing". This concept used to be called grid computing, computing clusters or server farms. There is extensive data transfer among the servers in these cloud compute clusters. The end result of this computational work, such as a list of search results, doesn't contain much data, but to calculate the relevance of a website, the page rank, you have to look through large amounts of data.

The demand for bandwidth rises in proportion to the speed of the servers and the number of servers in such a Cloud. With 10,000 servers that require 1 gigabit per second per server, the cloud network has to move 10 terabits per second. Of critical importance is that the switches allocate bandwidth fairly to all servers and connect them with very low latency.

Q: Do you build your own switch silicon for your systems?

A:No. In contrast to 10 years ago, today there are very good switch chips and network processors that there is no need to develop your own silicon, which is extremely expensive to do.

Q: What do you bring to the table?

A:We develop the network software. A switch needs to respond to a large number of protocols to operate correctly. We have developed a very modular and robust network operating system that we call EOS, which has separate processes for each task in the networking stack. If a process fails or gets updated, it does not affect the operation of the switch and the system continues without interruption. As a result our system is very stable. Further, EOS runs on top of a standard Linux kernel. This means we can run any other programme on the same switch, including customer specific solutions.

Q: How many computers can one switch handle?

A:Customers usually configure 20 to 40 computers per rack. Our rack-top switches have up to 48 ports, 40 of which connect to the computers in the rack and the rest connect to our core switch, which has hundreds of ports. This allows us to support very large clusters with 10,000s of servers. The computers are so fast nowadays that in many cases the network bandwidth has become the limiting factor. With our switches we offer customer a great way to increase overall system performance.