I did a bunch of testing with ARM (ThunderX) for an IPC workload using this codebase: github.com/sargun/wat. Unfortunately, it no longer runs on ARM, because I'm using inline assembly.

The ThunderX's power comes from the fact it's a 48-core CPU, which is awesome for web workloads. The problem comes in that inter-core transfer is ridiculously slow. To make a 64-byte RPC (return / response), was in the area of ~1100 nanoseconds, whereas x86-64 was on the order of 500 nanoseconds on a 2 generation old CPU. Testing on a more modern CPU cut the time further.

I'd love to see ARM either catch-up in single-core performance, or multi-core performance, but until then I don't feel like it's viable.

According to the article this CPU as compared to the ThunderX has 80% faster integer performance for the whole CPU and 2x faster integer performance per core - so major a improvement:

http://images.anandtech.com/doci/11189/APM-X-Gene-3-performa...

Turns out that number crunching isn't what my CPU is doing most of the time. :-/.

Interesting! Cavium's network processors running bare-metal have features to ensure no core is ever idle. Maybe at the expense of latency. The idea probably doesn't translate to running a bunch of virtual servers. You probably do better with a shared-memory abstraction than a network. Or, disappointing numbers may just reflect the fact that individual cores are slow. Bad news either way.

I imagine some being ready to sacrifice performance and going with ARMv8 for them not being flawed with technologies such as Intel AMT.

Some are but not enough to support anything commercial - at least that's what history tells us.

People say they will pay for quality but the vast majority eventually only care about price.

I worry that the only thing they seem to be bragging about is stream, which is generally the worst possible measure of general performance.