Abstract:

The so-called “Moore’s Law”, by which the performance of the processors will increase exponentially by factors of four every three years or so, is slated to be ending in 10 to 15 years due to the lithography of VLSIs reaching its limits around that time, and combined with other physical factors. This is largely due to the transistor power needs becoming constant and as a result, means to sustain continuous performance must be sought otherwise than increasing the clock rate or the number of floating point units in the chips, i.e., an increase in the FLOPS.

The promising new parameter in place of the transistor count is the perceived increase in the capacity and bandwidth of storage, driven by device, architecture, as well as packaging innovations: 

DRAM-alternative Non-Volatile Memory (NVM) devices, 3-D memory and logic stacking evolving from VIAs to direct silicone stacking, as well as next-generation terabit optics and networks. The overall effect of this is that the trend to increase the computational intensity as advocated today will no longer result in performance increase, but rather, exploiting the memory and bandwidth capacities will instead be the right methodology. However, such shift in compute-vs-data tradeoffs would not exactly be a return to the old vector days, since other physical factors such as latency will not change when spatial communication is involved in X-Y directions. Such conversion of performance metrics from FLOPS to BYTES could lead to disruptive alterations on how the computing system, both hardware and software, would be evolving towards the future.

Bio:

Satoshi Matsuoka is a professor at Tokyo Institute of Technology (TITech) and a leader of the TSUBAME series of supercomputers. Matsuoka built TITech into an HPC leader, adopting GPGPUs and other energy efficient techniques early on and helping put Japan on a course for productive exascale science. He is a fellow of the ACM and European ISC, and has won many awards, including the JSPS Prize from the Japan Society for Promotion of Science in 2006, the ACM Gordon Bell Prize for 2011, and the Commendation for Science and Technology by the Minister of Education, Culture, Sports, Science and Technology in 2012.