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Can anyone explain why Apple would be dropping Intel and doing ARM instead, instead of just, you know, doing their own thing? I find it hard to believe either t

by tomp 6y ago

Can anyone explain why Apple would be dropping Intel and doing ARM instead, instead of just, you know, doing their own thing? I find it hard to believe either that ARM is the (globally optimal) pinnacle of instruction set / CPU architecture possible, and that a $1tn company can afford to spin up its own CPU production line (competitor to Intel, a $250b company) but not its own CPU design department (competitor to ARM, bough by SoftBank for $30b) ?!?

basementcat 6y ago
An ISA doesn't just exist in a vacuum. There is also the compiler toolchain, runtime libs, developer mindshare and years of very smart people thinking about the ISA. A $1e12 company doesn't have to pick the "pinnacle" of ISA/CPU possible. They just have to pick one that is good enough to meet their financial goals.
newsclues 6y ago
Didn’t Apple invest in ARM in 1990?
jeppesen-io 6y ago
I think you fail to grasp the sheer amount of time to create a new instruction set, easily a decade to get to the level ARM is now. Not just the hardware, but debuggers, tooling etc etc. Can't see that paying off Also, the kernel codebase, which is shared with iPhones, will be able to target a single architecture
deleted 6y ago
[deleted]
jsnell 6y ago
The instruction set matters less for performance than people think. But it does matter a lot for the ecosystem: low-level hyper-optimized libraries for certain operations (think BLAS), tooling, developers understanding how to best write for it, etc. Creating all of that will take a long time no matter how much money you throw at it. For ARM, that ecosystem is probably the second best in the world, and in particular Apple has been building it up for themselves for more than a decade since the first iPhone. Additionally, sharing the ISA means that the ARM reference cores will always be available as a backstop if Apple's custom chips start running into trouble for whatever reason. IIRC, Qualcomm was doing a lot of hopping between full custom cores and ARM reference ones depending on which one happened to work better some particular year.
loser777 6y ago
ISAs are somewhat orthogonal to performance these days, so this move is more or less switching to Apple CPU designs. Apple has rapidly iterated and improved in-house designs since basically the A4 iPad.
deleted 6y ago
[deleted]
valuearb 6y ago
Apple effectively has its own proprietary ARM designs, best in the world, and production relationships with chip manufacturers to make them in huge volume. Dumping that for some clean sheet of paper design without real world customers, tool chains, and manufacturing to try to gain a tiny percent in performance and/or cost would be immensely foolish. It’s been speculated Apple could even license the x86 instruction set to include a x86 coprocessor in every one of their designs.
pritovido 6y ago
Because Apple's business is not doing "their own thing". Apple's business is taking something that already is proven to work, and integrate it into something that makes money. ARM is proven to work. It was designed for phones, tablets, routers, everything. That means you could go to a factory like TSMC and they can reuse in excess of 95% of their hardware chip templates. You can reuse work done in iOS hardware too. We are talking about freaking less than 10 nanometer scale designs!! The transistor's layout at those scales is not even square but calculated with quantum effects with very complex software, and retouched by hand with very expensive feedback using electron and X-rays microscopes. That also means you can reuse the compilers that already exist, the transpilers and the toolchain in general. Hardware designs need literally years of testing in very sophisticated machines(supercomputers) before you use them. Remember that if you make a mistake your entire die is wrong, million of dollars go to the toilet. And you always make mistakes before the design is mature. It is not software that you could update easily and cheaply. If you were to do your own thing , your chips would cost you 100x to 1000x to make just in money. It would also cost you orders of magnitude in time to market. Of course a $trillion company can waste money away(until there is no more money left) but probably they want their money to give profit and create wealth instead of consuming it.

by tomp 6y ago

basementcat 6y ago

An ISA doesn't just exist in a vacuum. There is also the compiler toolchain, runtime libs, developer mindshare and years of very smart people thinking about the ISA. A $1e12 company doesn't have to pick the "pinnacle" of ISA/CPU possible. They just have to pick one that is good enough to meet their financial goals.

newsclues 6y ago

Didn’t Apple invest in ARM in 1990?

jeppesen-io 6y ago

I think you fail to grasp the sheer amount of time to create a new instruction set, easily a decade to get to the level ARM is now. Not just the hardware, but debuggers, tooling etc etc. Can't see that paying off Also, the kernel codebase, which is shared with iPhones, will be able to target a single architecture

deleted 6y ago

[deleted]

jsnell 6y ago

The instruction set matters less for performance than people think. But it does matter a lot for the ecosystem: low-level hyper-optimized libraries for certain operations (think BLAS), tooling, developers understanding how to best write for it, etc. Creating all of that will take a long time no matter how much money you throw at it. For ARM, that ecosystem is probably the second best in the world, and in particular Apple has been building it up for themselves for more than a decade since the first iPhone. Additionally, sharing the ISA means that the ARM reference cores will always be available as a backstop if Apple's custom chips start running into trouble for whatever reason. IIRC, Qualcomm was doing a lot of hopping between full custom cores and ARM reference ones depending on which one happened to work better some particular year.

loser777 6y ago

ISAs are somewhat orthogonal to performance these days, so this move is more or less switching to Apple CPU designs. Apple has rapidly iterated and improved in-house designs since basically the A4 iPad.

deleted 6y ago

[deleted]

valuearb 6y ago

Apple effectively has its own proprietary ARM designs, best in the world, and production relationships with chip manufacturers to make them in huge volume. Dumping that for some clean sheet of paper design without real world customers, tool chains, and manufacturing to try to gain a tiny percent in performance and/or cost would be immensely foolish. It’s been speculated Apple could even license the x86 instruction set to include a x86 coprocessor in every one of their designs.

pritovido 6y ago

Because Apple's business is not doing "their own thing". Apple's business is taking something that already is proven to work, and integrate it into something that makes money. ARM is proven to work. It was designed for phones, tablets, routers, everything. That means you could go to a factory like TSMC and they can reuse in excess of 95% of their hardware chip templates. You can reuse work done in iOS hardware too. We are talking about freaking less than 10 nanometer scale designs!! The transistor's layout at those scales is not even square but calculated with quantum effects with very complex software, and retouched by hand with very expensive feedback using electron and X-rays microscopes. That also means you can reuse the compilers that already exist, the transpilers and the toolchain in general. Hardware designs need literally years of testing in very sophisticated machines(supercomputers) before you use them. Remember that if you make a mistake your entire die is wrong, million of dollars go to the toilet. And you always make mistakes before the design is mature. It is not software that you could update easily and cheaply. If you were to do your own thing , your chips would cost you 100x to 1000x to make just in money. It would also cost you orders of magnitude in time to market. Of course a $trillion company can waste money away(until there is no more money left) but probably they want their money to give profit and create wealth instead of consuming it.