Thanks to the new OpenMP specification, the HPC developer will soon have some new choices, but the path is not quite clear. The ability of OpenMP 4.0 to address both cores and accelerators is very attractive. Casting applications in this framework is a good choice if you expect a single SMP memory domain will hold enough compute horsepower for your needs. Just as the processor clock “free lunch” hit a wall (because of heat), so will the current just add cores “free lunch” (because of memory issues). Expecting a steady growth curve of x86 cores in processors is probably not a safe bet. Even now, memory contention limits how fast some applications will run on a multicore processor (i.e., applications stop scaling because of a memory bottleneck). Adding more cores only exacerbates this problem.
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