I question whether the CPU used in iphone is scalable. You are speaking of two distinct classes of CPUs: One is mobile, the other is Desktop. Right now, Intel's kaby Lake is almost five times more efficient than A10's high power cores. One reason is that the 25 watts chip inside iphones is very weak in real demands: For example, in tests which the hardware acceleration of their custom ARM is not a matter. For example, it only beats atom clovertrail+ 32 nm in 3d marks physics performance. It is not the only benchmark so, there are benchmarks which apple fails very badly, in addition to those famous good in. It means they certainly did use custom ICs rather than real CPUs which understand software well. Even now it is no more a secret Apple uses FPGA in iphone, circuits like for rendering HTML is very old Apple did to increase performance. But Intel's CPUs are made by an independent company and works across a lot of platforms without need for a driver or even complex optimizations. It makes a steady performance across many platforms. Whether it is OS or virtualization or programming languages or mobile/Desktop use. Intel's latest are king in both Desktop and mobile...
Intel's broadwell is so old, you must compare apple's a10 with it in real use, of course, it has less limitations... How do I say it? based on real use... My Laptop with haswell is very fast i7 quad core 37 watts, but in spite of it, 70% of battery use of my 4 hours laptop is by screen only, so, the CPU is much more efficient than screen. That's in windows 10 x64 with lots of programs on. Now, you suppose A10, this is like 90% of use is by CHIPs inside iphone (specially when using it mixed). Users complain about iphone 7 battery life extensively, one said if you run fitness app and run, it consumes 1% of battery every one or two minutes (or two percents in every one min/I don't remember well).
Intel's Kaby Lake is twice faster than Skylake. And Skylake? Intel Xeon E3-1240L v5: a 25 watts TDP CPU with 4 cores: How fast is it? Faster than quad core broadwell 65 watts and faster than haswell quad core 84 watts in every area. Price? Only $278...
Thanks!