Computer Modelling: Then and Now

Running experiments with global atmospheric models at the Department of Meteorology, University of Reading.
The change in computing infrastructure from 1979 to 2017.

The present UK national supercomputer for academic computing, a Cray XC30, is around 16 million times more powerful than the Cray-1 used in the early 1980s. This comes from a faster processor (clock period reduced by a factor of 34), the huge number of processors (>0.1 million) and chip/software design (multi-threading etc). Both machines were in the top 50 for performance worldwide when they were introduced.

Input/output early 1980s	Mainframe 1983: Cray-1S SN28 at Daresbury then ULCC Single 80MHz processor, 160 MFlops peak (photograph shows Cray-1 SN1 at Daresbury in 1979, after periods at ECMWF and Aldermaston)
Input/output 2017	Mainframe 2017: Cray XC30 at EPCC 118,080 processing cores, each 2.7 GHz, 2.55 PFlops peak