ABSTRACT
Of all possible performance-limiting factors in HPC, the most important one is data access. As explained earlier, microprocessors tend to be inherently “unbalanced” with respect to the relation of theoretical peak performance versus memory bandwidth. Since many applications in science and engineering consist of loop-based code that moves large amounts of data in and out of the CPU, on-chip resources tend to be underutilized and performance is limited only by the relatively slow data paths to memory or even disks.
