Technology and Computing: Today’s Software Paradigm will Break Down with Next-Generation Exascale Supercomputers

Both governments and businesses are working to develop the next level of supercomputing: exascale computing.  Since 2008 supercomputers have been operating in the petascale range.  Computerworld estimates that supercomputers will reach the exascale computing range by 2018, and most analysts agree that an exascale computer should be possible before the end of this decade.  Exascale computing is the order of processing capable by the human brain.   It represents 1 million trillion floating point operations per second, 1,000 times faster than today’s fastest machines based on petaflop technology.  An exascale computer would be capable of a total processing equivalent of about 50 million of today’s PCs.

Patrick Dreher, chief scientist in the HPC technologies group at DRC, said that the move towards exascale computing is driven by “demand for better, more accurate, more detailed computational simulations across the spectrum of science and engineering. It’s a very cost-effective way to design products, research things, and much cheaper and faster than building prototypes.”

But in order for next-generation computers to scale into exascale range, newer hardware techniques are being applied to build machines.  They new-style machines will force software to change so as to be able to take advantage of the technology that enables the new speeds.

Horst Simon, the Deputy Director at the Lawrence Berkeley National Laboratory’s National Energy Research Scientific Computing Center (NERSC ), said that even if exescale computing speeds are reached, it will take some time in order to be able to use those machines efficiently.  Why?  Because exascale supercomputing fundamentally breaks “our current programming paradigm and computing ecosystem.”

Mike Papka, director of the Argonne Leadership Computing Facility, said that “as you go back and try to adapt legacy codes to modern architecture, there’s a lot of baggage that comes along.  It’s not clear to me what the path forward is.”

Jack Dongarra, professor of computer science at the University of Tennessee, said that “you can’t wait for the exascale computers to be delivered and then start thinking about the software and algorithms.  The exascale computers are going to be dramatically different than the computers we have today. We have to have the techniques and software to effectively use these machines on the most challenging science problems in the near future…  Today’s supercomputers have processor counts in the millions. Tomorrow’s exascale computers will have roughly a billion processors. In addition, the general makeup of the machines will differ dramatically through the use of multiple central processing units and hybrid systems to overcome barriers limiting today’s supercomputers. These barriers include large amounts of heat and power consumption, leaking voltage and a limited bandwidth of data through the pins on a single chip.”