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Comment by holstvoogd | Hacker News Reader

hmm, I feel ARM performance is a bit like nuclear fusion. It's always the next generation that will deliver an order of magnitude performance increase. Yet some how ARM single core performance is still shit compared to x86. (No matter how much I hope and pray for that to change, cause x86 needs to die)

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I'm afraid you're simply wrong here. Single core performance of the (now sadly deceased) Qualcomm Amberwing was incredible, easily Xeon-like. And it had 46 cores per socket. The Cavium ThunderX2 also has great single core performance coupled with many more cores than you can get on an Intel chip. Apples iPhone cores are also supposed to be good. (Edit: These are ARM cores, but not ARM-as-in-the-company designs)

Interesting, I was mostly thinking about the ARM's own cores, but never _really_ looked into the broader ecosystem.

From my personal experience, Apple chips are fast, but I can't really compare that to anything else. JS benchmarks match desktop performance, but that is not really what I was/am interested in. I've tried some 'cloud ARM-based metal servers' which promised to have similar performance as intel Atom cpu's basically, but they felt at least 10 times slower. So I gave up on the whole concept.

But I guess the take-away is, those specific systems where slow not so much ARM in general. I mean, it does make sense that there is some scale difference between a Xeon core vs a core meant for mobile use now that I actually think about it ;)

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.

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.

Is this true for comparable TDP processors? Speaking as the owner of one of the few x86 Android phones, the Intel performance isn't better on small devices.

Nah, I wasn't thinking. Comparing what are essentially mobile cores with i7/9 desktop cores is just BS. Please disregard my previous statements ;)

An iPad Pro's single-threaded geekbench performance is better than the 8th-gen i7 in my laptop, according to geekbench. Multithreaded is better on my laptop. This is comparing the iPad to just the CPU; my actual model is almost certainly better (particularly if you consider thermals). This comparison is also with Apple's additional (not inconsiderable) design work on top. I also sincerely doubt an iPad could sustain this. But the point is the same: an a12x macbook pro could be a serious contender.

Nvidias single core performance is even worse, yet their GPUs sell great. Lots of workloads have no need for individual fast cores

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