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Comment by master_crab | Hacker News Reader

The M-series are ARM chips based on the A series from the iPhones. Therefore Apple had ten years of chip design (plus the prior decades of ARM history) to rely on. The GPUs and modems were a much more recent effort.

(My take. happy to be corrected by someone with chip design experience who can comment.)

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I would argue their architecture choices long term proved to be prescient (RISC, ARM, etc) and securing TSMC production capacity (beating competitors to the punch) aided them as well.

Their main architectural choice was not about "RISC" or "ARM" but it was choosing "Brainiac" over "Speed Demon", i.e. setting the goal to execute a great number of instructions per clock cycle at a moderate clock frequency, instead of executing a moderate number of instructions per clock cycle at a high clock frequency (the latter variant results in lower fabrication costs, which is why other companies were reluctant to pursue the same choice as Apple).

A high IPC is much easier to achieve when the instructions have a fixed-length encoding, so this RISC principle followed from their main choice.

ARM was chosen for the Newton, then the iPods, then the iPhone and so on. Apple’s experience with ARM has a long history. Same applies to RISC. Apple didn’t leave PPC because it was a dead-end. They went with Intel because IBM was not interested in developing a low power PPC just for Apple. IBM wasn’t (and still isn’t) even interested in developing a POWER chip for desktop workstations. If there are POWER machines that can be turned into workstations, it’s a side effect of them being targeted at entry-level half-rack systems.

The iPhones had GPUs too. As far as I'm aware, the GPU design in the M-series chips are directly descended from the iPhone GPU in the exact same way the CPU is.

Prior to the A11 chip they used PowerVR designed GPUs. They weren't done in house.

Ah I see, good to know.

Based on Alyssa Rosenzweig’s reverse engineering, the current GPUs are still descended from PowerVR IP

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