It has nothing to do with expertise. Based on latest ARM servers benchmarks, 16 core CPU, without Hyper Threading is consuming up to 80W under load. While being slower than equally power efficient, but 8 Core CPU, at the same tasks. Call it lack of software optimization, call it hardware performance. Whatever.
Except again, that's not Apple's ARM CPU. I know it's a frustrating grey area because Apple doesn't ship a big ARM CPU to compare. But ARM performance is not blanket. Different ARM CPUs are optimized very different.
Heck, some ARM CPUs don't even support out of order execution which can be a real problem.
ARM CPUs are hitting Diminishing Returns field when scaled up. Its not up to Apple to fix this.
Its up to ARM to fix this.
Ehhhhhhh.
It really depends what we're talking about.
Most ARM CPU cores are tremendously dumb. It's getting better, but the cores themselves have traded low complexity for power efficiency. Apple has been building more complex ARM cores that may actually not be as efficient, but scale better.
Apple doesn't usually focus on continuous performance for power efficiency. They believe that if the work is cleared as fast as possible, the CPU can go back to idle, and that is better for performance. That leads to designs that are more comparable to desktop CPUs.
Is that at all related to what you're talking about? Not sure. I'm working with generalities here still.
Instruction length. And you know that perfectly well. They may score brilliantly in Geekbench, which executes simplest instructions.
But when you will put the load on those CPUs, the picture may be completely different.
I didn't really want to get into it because it's proprietary information that I can't share, which is kind of unfair to the thread, but I spend a lot of time benchmarking "real world" code on Intel vs ARM, and if there is some sort of hidden performance trap on Apple's ARM CPUs... I'm not seeing it. The only thing I generally see, which is borne out in public benchmarks, is that Intel is still the master of vector instructions.
The only thing to really watch for with Apple CPU benchmarks is they optimize the CPU to spike performance in bursts. But on an iPad that's far less common, and Intel is doing the same thing anyway. Don't know about AMD.
I also think that if Intel was at 7 nm, we might be in a different place right now. Intel is very good at optimizing what they do, and they mostly seem to just be getting hurt by not being able to scale the actual chip beyond 14 nm. I think Intel is probably better at design than both AMD and Apple, but they just can't make up that process gap.
[automerge]1575334934[/automerge]
People need to stop being hung up on die size and benchmarks. Die size can be good for reducing power draw but not the end all be all to silicon performance. Transistor density, lithography methods (e.g. self aligned quad patterning), and instruction sets (e.g. various AVX sets) all matter as well as die size. Benchmarks can be useful as a proxy to performance but processor X being 3% faster than processor Y per core in raw number crunching doesn't necessarily equate to better performance for specific tasks. Unless you have tied your identity to the manufacturer of a specific component in your computer it just shouldn't matter this much. The question should be will this do the job I need it to in a manner that's effective for me.
It's also worth bringing up that Apple's CPUs are a cluster of processors. We've just been talking about the ARM cores, but there are tons of co-processors on the package that could be helpful.
Doesn't apply quite as much to the Mac Pro in since Apple has an entire board to work with. And stuff like Afterburner. But part of the strength of Apple's chipset is they can add dedicated co-processors for specific tasks.
There's a lot of specific tasks (like Metal, or transcoding, or machine learning) that have little or nothing at all to do with the ARM cores.
But... also could be interesting to see a fusion of Apple's custom task specific cores with AMD's custom designs.