Basic HTML version of Foils prepared 21 October 1995

Foil 24 Switches versus Processor Networks

From New CPS615 Foils-- B 28 August 95 CPS615 Basic Simulation Track for Computational Science -- Fall Semester 95. by Geoffrey C. Fox


1 Note that the processor networks such as torus or hypercube can be used to build switches when one does not put processors on internal nodes but rather "just" switch chips.
2 Thus switches are discussed with same trade-offs -- store and forward, circuit-switched as processor networks.
3 Switch based machines have typically the same delay (travel time) between any two processors
4 In Processor networks, some machines can be nearer to each other if fewer hops
5 BUT in all modern machines, low level hardware essentially makes all these architectures the SAME. There are only two times of importance corresponding to DATA LOCALITY or not
  • Time to access memory on processor
    • This further divides into time to get to main DRAM and time to get to cache
  • Time to access memory off processor
  • Here time covers both latency and bandwidth.

in Table To:


© on Tue Oct 7 1997