...maybe in 2 two year ARM reaches x86 performance, not now, not next year not even driven by Apple...X86 to disappear, or going after ARM? I think it was a possibility until it recent architecture changes planned for 2019 (just when is expected first ARM chips will reach current X86 IPC non-SIMD performance)...what I see is AMD migrating to ARM after ZEN decline in 2019....
How could x86 possibly disappear -- regardless of whether Intel makes certain future architectural changes? Today the datacenter is nearly 100% x86. If you examine this table of top transaction processing results, nearly 100% of the fastest servers are running Xeon x86 CPUs:
http://www.tpc.org/tpce/results/tpce_perf_results.asp
Recent academic studies have shown at the upper performance levels there is no efficiency or scalability difference between ISAs (Instruction Set Architectures) -- even between ARM and x86:
http://research.cs.wisc.edu/vertical/papers/2013/hpca13-isa-power-struggles.pdf
IF ARM/Apple CPUs *could* be scaled up to the performance level of the 24-core Xeon E7-8890 v4 (which does about 3,100 Linpack gigaFLOPS), they would be burning just as many watts and would be no cheaper to manufacture. There is no credible roadmap that ARM/Apple CPUs can be scaled up to this performance level, but IF they were, there would be no architectural, performance or efficiency advantage.
IF they could ever reach that performance level it would be a competitive supplier to Intel and that might create pricing pressure on Intel which would benefit customers. But that would not be due to some architectural, performance or efficiency advantage, but solely as an additional CPU supplier. But for that to happen ARM-architecture CPUs must get there first.
Google, Facebook and other gigantic datacenters are constantly examining and testing alternatives to x86 servers. If ARM, Apple, IBM, or Oracle could supply a high-end CPU solution which was cheaper, faster or more efficient, they would deploy those beyond a limited test. But so far that is not happening.
IBM is already far ahead of ARM/Apple in CPU performance with the Power8 and upcoming Power9 CPU family. However even those have not successfully challenged Intel's dominance in the high-end workstation and server space, so the idea that x86 will somehow fade away anytime soon is without much basis.