In my experience, many I/O bound applications tend to benefit less from parallelism, but still usually benefit from a fast (single threaded) core - there's ofte

In my experience, many I/O bound applications tend to benefit less from parallelism, but still usually benefit from a fast (single threaded) core - there's often still quite a bit of cpu processing in supposedly I/O bound tasks. As in: you're still better off getting a fast CPU, you just don't need a bazillion cores. Since perf/watt is still poorer in general on ARM cores you'd need to be very very sure that you really don't need any CPU for that to be worth it. Also; most of these CPU's aren't designed in a vacuum: faster CPUs tend to have better I/O subsystems. E.g. memory latency (which is I/O from a CPU's perspective) is much, much worse on ARM, probably because it hasn't historically mattered as much. So I'd expect arm to make sense on special purpose I/O related stuff, where you can be sure the limitations aren't an issue. Do some fast e.g. SSDs include ARM chips? Perhaps