the problem is that many low-end and middle-end android tablets are based on Cortex A53 which is a slow in-order CPU (but very power efficient).... The Flash storage performance is also very important for user experience and is often left behind in reviews

And what's often an even bigger deal is many of the low-to-mid end devices have very, very little cache (some have no L2 cache, even!).

Wait, what? I'm trying to think of an application SoC from the past 8 years that doesn't have an L2 cache.

I'm struggling to find the one I was thinking of, maybe I'm just imagining it. Most things I can find are 256kB/core, which is the same as most Intel chips (though the A11 is over 1MB/core!).

Yeah, you borderline need an L2 for any multicore systems. L2's main job on most designs is coherency and reducing the explosion of bandwidth needs from the cores all vying for the main memory bus.

Yeah, I was amazed when I was told it before. Obviously should've checked their sources. :)

They are mostly painfully slow because they do not even use the previous best Cortexes.

You need to compare few things other than raw performance. Latest Apple chips are humongous for ARM based SoCs.

This is in big part due to them having bigger caches than some server CPUs.

I was curious about this claim so I looked some numbers up. The latest A11 chip has 8MiB of L2 cache. I could only find a small handful of xeon models with 6MiB of cache while almost all of them contain equal or greater amounts of L2 cache. The chip does not have L3 cache so there is nothing to compare here. The A10 has total package cache less than 8MiB (split into L2 and L3). So I'm not sure this is a good explanation of the performance or size difference.

From what I can tell, while cache is still a large portion of the area, GPU die space is quite large now. The CPU performance seems to be due to expanded execution ports leading to more dispatched instructions per cycle, which is generally a good idea as long as one can keep the execution ports fed with a good amount of speculation in other stages of the pipeline.

You also have to add SRAM on the GPU, decoders, and etc that adds to 13mb

Not so humongous they can’t fit in one of the thinnest phones.

I think apple had this huge lead when they introduced x64 out of the blue. Over time other players will catch up, I guess. But yeah, apple's engineering team have been doing an excellent job. I'm excited about google's inclusion though. They already make great tpu's.

Pretty sure you meant ARM64 not x86 :)

But yeah, the SoC in the iPhone 5S was crazy fast at the time, plus they have other advantages like Secure Enclave, and a smartwatch with ACTUAL all day battery life. I owned a Sony phone with a Snapdragon 810, which was Qualcomm's first high-end 64-bit chip... and it overheated at the drop of a hat. The phone was more or less unusable in Australian summer. Everything I read at the time indicated that Apple really caught the rest of the industry off guard.

Even Wikipedia puts it pretty bluntly:

"The first 64-bit SoCs, the Snapdragon 808 and 810, were rushed to market using generic Cortex-A57 and Cortex-A53 cores and suffered from overheating problems and throttling, particularly the 810, which led Samsung to stop using Snapdragon for its Galaxy S6 flagship phone."

Apple is so ridiculously ahead in the ARM chip market... imagine if they'd sell to 3rd parties and the single thread performance on these laptops was 2x. Makes me wonder if they are about to make the same move on the lower speed MacBooks.

They already have a arm chipset working as controller in the latest iMac. I'm sure their end goal would be to get rid of intel as soon as they can. Using intel chipset gives them uncertainty. It leaves control out of their hand.

Yes exactly.

It may only be similarly effective, but much more efficient.