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Comment by pzo | Hacker News Reader

I benchmarked few image processing algorithms (opencv) on my iphone xs. I was surprised processing was faster than on my quadcore i7 macbook pro 2012. Sure cpu is 6 generation behind but there haven't been much performance improvements in the last 7 years on x64. Probably around + ~50% single thread.

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Image processing is probably offloaded to some sort of custom silicon. If that is the case, then the generational performance uplift would be massive.

Consider this:

Decoding a big fat X265 file on your 2012 MBP would be atrocious because it doesn't have hardware X265 decode, but decoding it on your XS would probably be fine.

That could be true for only some algorithms but I have investigated the source code as well and on ARM it uses only NEON instructions if available (but its equivalent of SSE and AVX2 on x86 anyway).

The result is the same with my own crafted image processing algorithms using single core. Apple makes really fast CPUs.

That’s six years of difference, though. That’s not a fair comparison.

How much has x86 performance increased over the past six years?

Not that much. Each generation there was maybe 7% perf improvement so in 6 years: 1.07^6=1.50. Improvement was mostly with adding more cores.

This ~1.5x in single thread performance improvement matches with stats from geekbench.com benchmark:

my macbook pro 2012 cpu: i7-3615QM => 3093 single thread [1] equivalent current gen cpu with same TDP (45W) and similar clock (2.3GHz): i7-8750H => 4617 single thread [2]

[1] https://browser.geekbench.com/processors/741 [2] https://browser.geekbench.com/processors/2144

Before or after meltdown, spectre, l1tf, foreshadow, zombieload, ridl, and fallout patches? I would honestly guess that these new round have cost a huge amount of progress. I certainly won't be applying the latest three; I spent too much on a nice machine to have it perform as though it were four years old.

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