The penetration of the supercomputer market by microprocessor based supercomputers is another often debated issue. The TOP500 list again delivers hard data, which come somewhat as a surprise. In Table 6 we present the number of installations for the different processor technologies used among the TOP500 . The custom processor category includes all machines manufactured by Cray Research (with the exception of the T3D machines based on the Alpha processor by DEC), all machines manufactured by IBM (with the exception of SP-1 and SP-2 machines), all machines from Convex (with exception of the Exemplar machines), as well as all products by Fujitsu, Hitachi, NEC, Siemens-Nixdorf (Fujitsu), Ncube, and KSR. Semicustom machines are all entires by TMC and Meiko, since both use a mix of commodity and custom technology. All others are counted as microprocessor based.
Overall micros account for 239 of all installed supercomputers. The installed base in the U.S. is significantly higher. In the U.S. and Europe the ``killer micros" are already the largest category, whereas in Japan MPPs are considerably underrepresented.
If we consider architecture used among the TOP500 , there emerges a different picture. In Table 7 the different architectural choices for installations machines among the TOP500 is given. The PVP category includes all machines manufactured by Cray Research (with the exception of the T3D machines), all machines manufactured by IBM (with the exception of SP-1 machines), all machines from Convex (with exception of the Exemplar), as well as all machines from Fujitsu, Hitachi, NEC, and Siemens-Nixdorf (Fujitsu). The SMP category consists only out of the Silicon Graphics Power Challenge systems. All others are considered MPPs.
Table 6: Processor Technology (in number of installations).
Table 7: Architecture (in number of installations).
We can see several surprising findings. In 1994 MPPs moved ahead and are now the largest architectural category. SGI made a very strong showing in the SMP category with installing 54 new machines in 1994 alone. The move towards microprocessors is far less pronounced, however, with TMC out of the hardware business, some 70 installations are eventually up for grabs, and in all likelihood they will go towards microprocessor based systems. Thus we expect in 1995 this trend to become completely clear. As always, the U.S. is leading this trend.