Comments by "Mikko Rantalainen" (@MikkoRantalainen) on "Is Functional Programming DEAD Already?" video.

  1. Many parallelization claims for automatic parallelization totally ignore caches in modern CPUs. All the cache-compatible synchronization primitives are simply too slow to parallelize fragments where the synchronization takes more time than the actual execution of the fragment. And the faster the CPUs get, the more expensive the minimal synchronization gets when the cost is expressed in potential instructions that can be executed by the current thread. The higher the IPC the more expensive the synchronization tied to base clock of the CPU gets. And the synchronization must be tied to base clock to be synchronous over all cores. As a result, automatic parallelization nowadays focuses more onto SIMD than whole threads because SIMD doesn't require similar level of synchronization because it all happens in one L1 cache on the local core.
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