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Comment by webaholic | Hacker News Reader

ARM should gain about 30% in a single gen to be competitive with Apple/Qualcomm processors. It's going to be interesting to see if they can achieve this. Ultimately, competition is good for the consumer. Android phones are so far behind Apple, it is not funny anymore.

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They are not far off.

The Cortex X4 Running at 3.3.Ghz on a N4 gets GB6 ~2250. #681.8/Ghz

The Apple A17 Running at 3.8 Ghz on a N3 gets GB6 ~2950. #776.3/Ghz

On a clock per clock basis, A17 is only about 14% faster. Consider X4 had 15% IPC uplift and resulted in real world 11% performance improvement on GB6. And they are claiming X5 would have the largest YoY IPC uplift, which I think we could consider to be 15%+ or 20%, a Cortex X5 would have similar if not slightly better than A17 performance on a Clock to Clock basis.

And it would be good enough for Microsoft / ARM PC.

Clockspeed is influenced by design choices. ARM can't just crank up the clock speed to match Apple's chip.

Another thing I'd like to see is perf/watt.

Apple lets their CPUs and GPUs run at a higher max frequency/power draw, but you're absolutely right that in clock-to-clock performance they're only marginally better in both CPU and GPU performance.

If you clock CPUs low enough, many CPUs in the past could match Apple in clock-to-clock performance. This is because clock speed does not scale with performance.

>This is because clock speed does not scale with performance.

You may want to have a word with AMD and Intel about that.

>many CPUs in the past could match Apple in clock-to-clock performance.

Are we talking about synthetic benchmarks or real world work loads.

Clock speed does not scale linearly with performance.

Synthetic. Something like Geekbench.

"The absolute top end Android processors get about 76% of the performance of Apple's processors" isn't the strong argument you may think it is tbh. Per clock performance is uninteresting (it's not like performance is linear with clock speed anyway, and target clock speed is a huge part of the CPU, so I don't even understand why you'd want to adjust for it even in principle in this comparison).

>it's not like performance is linear with clock speed anyway

It doesn't scale well beyond certain clock speed, which is why extreme overclocking dont get you a linear performance boost. But at the ranges mobile SoC it is about as linear as it gets. i.e Clocking your SoC from 3Ghz to 3.3Ghz will get somewhere around ~10% improvement in most workload.

>and target clock speed is a huge part of the CPU

Target clock speed is a huge part of considering for power usage.

As you suggest, the performance benefits of increased clock speeds is highly workload specific. I agree. It's roughly linear for some workloads up to a point, and highly non-linear for other workloads (especially memory bandwidth constrained workloads, which is a relevancy case given that it's SoCs we compare, not stand-alone CPUs).

Yes, target clock speed is a big part in considering power usage, but also fab process, memory architecture, etc. Adjusting for clock speed makes no sense, though adjusting for power consumption might.

Per-clock performance is THE metric. Apple can't sustain those peak clocks for more than a few seconds before throttling down. Once both chips are running at a sustainable 2-2.5GHz, the IPC starts mattering a lot.

If Apple can't sustain those clock speeds for long, that's reflected in the benchmark result. Benchmarks and real-world performance are the only metrics which matter in the end.

And higher clock speed doesn't proportionally improve either real world metrics or benchmark results, so "benchmark score divided by clock speed" is a useless metric.

Geekerwan has a great review that covers this in their iPhone 15 Pro review.

https://www.youtube.com/watch?v=iSCTlB1dhO0

The CPU peaked out at 14 Watts in multicore Geekbench. That's close to the peak CPU power consumption of the entire M1 chip in devices many times larger than an iPhone.

GeekerWan had it throttling 200-300MHz when simply running specInt/specFP. It essentially throttles down to the same speed of the iPhone 14 at slightly higher wattage.

For mobile devices, real-world peak CPU performance hasn't gotten much better than my aging iPhone 12 because most of the extra performance has come at the expense of heat/power.

Just want to say thank you. Sometimes I get tired and I can't be bothered to do their homework to get all the links for them.

But I am glad on HN people will fill the gap.

I assume this comment is just here to supply various vaguely CPU-related technical info in case someone is curious, not to argue against my point? Because if it's the former then that's fine, but if it's the latter it doesn't really hit the mark

So the A17 still benchmarks over 30% faster than the Cortex X4 in single threaded tasks. Sounds about right based on my subjective experience.

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