Re:Intel Lines Up ThunderX ARM Against Xeons
by emn13 on Thursday June 09, 2016 @02:56PM
(#11871503)
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
AFAICT the benchmarks seem to focus on traditional use cases like CPU-bound/memory-bound computation. But the ever-growing use case is the physical hardware that underlies the commercial "cloud computing" focus. IMO much of that market is running I/O-bound code and if I were sourcing hardware for one of those providers I would want to offer a tier which could serve enormous numbers of clients on a single node.
Power consumption is another huge element of data center costs and scaling up ARM-based servers is likely to reap a big savings.