Transputer benchmark tests

The transputer is a powerful processor designed to be used as a component in multiprocessor systems. In this paper the transputers processing power is compared to other computer systems and its communication capacity is evaluated. The benchmarks programs test how well a processor performs scientific computation. The test programs are short sequential Fortran and Occam programs, which are executed on a number of computer systems. The communication test programs send data over links and measures the communication capacity under different circumstances. The results from the benchmark tests are compared and evaluated. The Inmos IMS T800 transputer [Inmos1] was announced in 1987. The transputer was designed to be used as a component in multiprocessor systems, by connecting a number of transputers to each other via its communication links. An arbitary number of processors can be connected into a network, thus forming a very powerful machine to a very low cost. There is no upper limit on how many transputers can be connected to each other, as there are no global shared resources in the system. The communication links are point-to-point links connecting two processes to each other. According to Inmos, the IMS T800 transputer has a performance of about 1.5 MFLOPS or 10 MIPS [ShTh]. However, because the transputer has a RISC-like architecture, it is difficult to compare the performance to other processors as measured in millions of operations per second. The performace measured as millions of floating-point operations per second is easier to compare between different computer systems, but the tests are very dependent on the used benchmark program. To get a reliable performance comparision, the same program should be executed on all compared systems. The purpose of the benchmark programs is to give an idea of how effective the transputer is. The tested transputers are IMS T414 and IMS T800. The T414 transputer has a 32-bit processor, 2 Kb internal RAM and 4 serial communication links. The T800 transputer has a 32-bit processor, a 64-bit floating-point processor, 4 Kb internal RAM and 4 serial communication links. The benchmark programs test how well the processors can perform scientific computing. The results should not be used as an classification of processors to state that a processor or processor combination is better than an other. The main idea is to give an overall picture of the differences in performance. One of the main factors affecting the overall performance of a transputer network is the communication capacity of the network. Each transputer has four bidirectional links which operate on a speed of either a 10 or 20 Mbits/s. The transputer can communicate bidirectionally on all four links and execute calculations simultaneously. The results from the link tests represent the actual communication capacity in which one link can operate in a real application. Transputer benchmark tests 2 The benchmark tests were performed on Hathi-2, a reconfigurable general purpose 100 transputer system [AM]. The Hathi-2 system is well suited for program development and testing due to its high flexibilty and availablity.