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How many billions of transistors in an iPhone processor?

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Re: How many billions of transistors in an iPhone processor?

#161

Post by yieldcrv »

kccqzy wrote: post #125
yieldcrv wrote: post #124

Earlier quoted context omitted.

hm, I dont feel the same way you should do some coding closer to the chip some bitshifting, some bit level manipulation you dont have to be good at assembly, just do a hello world and make a mental visualization of the registers being hit look up the OPCODES in your specific chipset , make some code to hit that specifically make a process that does it as fast as possible and benchmark it, do it faster or slower on a…

That's not even close to the chip. Dabbling around with the ISA doesn't tell you much about the micro architectural features of the chip. I'm sure "do some bit twiddling" is absurd advice for someone who has written a driver.

is all of it absurd advice? its about breaking abstract problems into smaller digestible problems to get a mental map

I dont think you need to write a driver for that map

Re: How many billions of transistors in an iPhone processor?

#162

Post by pzber »

mlsu wrote: post #48

I've often struggled to really "grok" how complex chips are. They all kinda look the same. I write software, so I know how complex that is, but like the device itself -- it's this little black box. What's the difference between one little black box and another? Most people don't even get that far; they think the computer is the screen that lights up. I've been reading datasheets a lot at work. The datasheet for an ST…

Beautifully written!

Re: How many billions of transistors in an iPhone processor?

#163

Post by joshxyz »

mlsu wrote: post #48

I've often struggled to really "grok" how complex chips are. They all kinda look the same. I write software, so I know how complex that is, but like the device itself -- it's this little black box. What's the difference between one little black box and another? Most people don't even get that far; they think the computer is the screen that lights up. I've been reading datasheets a lot at work. The datasheet for an ST…

i do web development, not versed on the iot stuff.

i tried to read an Espressif ESP32 manual, blew my fucking mind on how complex it is relative to how cheap it is.

Re: How many billions of transistors in an iPhone processor?

#164

Post by patterns »

Related to this is I watched a fairly recent talk by David May who worked on the implemention of the transputer in the late 80s together with Tony Hoare:

https://m.youtube.com/watch?v=lXUWmHgLiyU

At the end of the talk, he mentions the staggering complexity of the design and manufacturing of chips with billions of transistors. We have long reached a point where nobody fully understands how the chips work. IIRC, only two companies can do the manufacturing.

That modern chips work at all almost seems like a miracle. Do we really need chips this complex?

Re: How many billions of transistors in an iPhone processor?

#165

Post by rwmj »

yieldcrv wrote: post #124
mlsu wrote: post #48

I've often struggled to really "grok" how complex chips are. They all kinda look the same. I write software, so I know how complex that is, but like the device itself -- it's this little black box. What's the difference between one little black box and another? Most people don't even get that far; they think the computer is the screen that lights up. I've been reading datasheets a lot at work. The datasheet for an ST…

hm, I dont feel the same way you should do some coding closer to the chip some bitshifting, some bit level manipulation you dont have to be good at assembly, just do a hello world and make a mental visualization of the registers being hit look up the OPCODES in your specific chipset , make some code to hit that specifically make a process that does it as fast as possible and benchmark it, do it faster or slower on a…

Better advice would be to look at some of the open source RISC-V cores. They are nowhere near as complex as Apple's Axx silicon (probably not even 0.1%) but they demonstrate at least some of what goes on at the lower levels.

Re: How many billions of transistors in an iPhone processor?

#166

Post by grishka »

mlsu wrote: post #48

I've often struggled to really "grok" how complex chips are. They all kinda look the same. I write software, so I know how complex that is, but like the device itself -- it's this little black box. What's the difference between one little black box and another? Most people don't even get that far; they think the computer is the screen that lights up. I've been reading datasheets a lot at work. The datasheet for an ST…

If you want to gain a deeper understanding of how computers work, write an emulator of something relatively simple — GameBoy for example. This is kinda disillusioning. With the bugs you'll inevitably make, you'll understand how very, very, very dumb computers actually are. A CPU just fetches an instruction from memory, executes it, and updates the program counter. It does this indefinitely, for as long as power is applied. No magic whatsoever.

The GameBoy CPU is simple and easy to understand, sure, but modern ones are built upon the same basic principles, it's just that they run at much higher clock speeds and add lots and lots of parts (caches, pipelining, speculative execution, register renaming, multiple ALUs, SIMD ...) to execute as many instructions per clock cycle as possible. Also virtual memory support — MMU, TLB, all that stuff.

For the other side, if you want to build a CPU out of logic gates, there was a web-based game where you did exactly that. I don't remember the URL, sorry.

Re: How many billions of transistors in an iPhone processor?

#167

Post by lynguist »

grishka wrote: post #166
mlsu wrote: post #48

I've often struggled to really "grok" how complex chips are. They all kinda look the same. I write software, so I know how complex that is, but like the device itself -- it's this little black box. What's the difference between one little black box and another? Most people don't even get that far; they think the computer is the screen that lights up. I've been reading datasheets a lot at work. The datasheet for an ST…

If you want to gain a deeper understanding of how computers work, write an emulator of something relatively simple — GameBoy for example. This is kinda disillusioning. With the bugs you'll inevitably make, you'll understand how very, very, very dumb computers actually are. A CPU just fetches an instruction from memory, executes it, and updates the program counter. It does this indefinitely, for as long as power is ap…

> you'll understand how very, very, very dumb computers actually are

That’s not true for any post 1995 desktop CPU.

They just adhere to that model and pretend that that’s all they’re doing but in reality there’s layers of supercomputers inside the CPU: micro-op cache, branch predictor, reorder buffer, rename buffer.

They extract hidden parallelism out of the code, run it in blazing fast multiple instructions per clock cycle (!), and pretend that nothing out of the order happened.

CPUs are extremely complex and extremely smart. They can have errors in their implementation where the unseen branches that it executed can be accessed by some processes, etc. But there’s nothing dumb about CPUs. They are made of a million man-hours of engineering.

Re: How many billions of transistors in an iPhone processor?

#168

Post by 1letterunixname »

olliej wrote: post #18

I vaguely recall (many years ago) some GPU (a Matrox one iirc) coming out and it being a huge deal because of how many transistors it had. I think it may have been an amazing 100 million. Times have changed :D

MHz->GHz wars. This caused Intel and AMD to chase hyperdeep pipelines with terrible stall characteristics and awful cycle efficiencies.

You're misremembering. Matrox cards were also terribly slow in DOS and anything adjacent to 3D. I own several models with SGRAM. Even GeForce 2 GTS: 25m transistors. G200: 10m. Voodoo2: 4m.

Re: How many billions of transistors in an iPhone processor?

#169

Post by ben_w »

causi wrote: post #158
Shawnj2 wrote: post #155

Earlier quoted context omitted.

I think a moon base is actually more useful because there’s actual commercial use cases to a moon base like mining etc. and not only that but doing a mars mission is far easier and cheaper if you already have a moon base since you can make rocket fuel on the moon for cheaper in terms of delta-V if you can come up with a hydro lox chemistry design.

What could you mine on the moon that would be worth transporting home?

Back when people were suggesting mining it for helium-3, I remember reading a blog post that claimed the best way to get it out of the regolith would produce ridiculously high-purity metals as a side product.

It then went on to point out that the particle density of helium-3 in regolith of was so low that, despite it being a fusion fuel, it made more sense to catapult the ingots to earth and (1) magnetically decelerate them for energy, and/or (2) burn them.

I suspect one of the best things you can build on the moon and not on Earth is an orbital ring[0]. Well, two rings, first you build one orbiting the moon, learn what the failure modes are and how to mitigate them, then you use that learning experience to export the parts for another to Earth… but I am just straight up assuming that the cost of a moon-based factory won't blow away the cost savings from the difference in delta-v going down to LEO from the Moon (with or without a lunar orbital ring) vs. going up to LEO from the surface of the Earth.

(Also: not mining, but I imagine it would be a great place for dangerous research, inspired by all the people suggesting COVID leaked out of a gain-of-function research laboratory).

[0] https://en.wikipedia.org/wiki/Orbital_ring

Re: How many billions of transistors in an iPhone processor?

#170

Post by grishka »

lynguist wrote: post #167
grishka wrote: post #166

Earlier quoted context omitted.

If you want to gain a deeper understanding of how computers work, write an emulator of something relatively simple — GameBoy for example. This is kinda disillusioning. With the bugs you'll inevitably make, you'll understand how very, very, very dumb computers actually are. A CPU just fetches an instruction from memory, executes it, and updates the program counter. It does this indefinitely, for as long as power is ap…

> you'll understand how very, very, very dumb computers actually are That’s not true for any post 1995 desktop CPU. They just adhere to that model and pretend that that’s all they’re doing but in reality there’s layers of supercomputers inside the CPU: micro-op cache, branch predictor, reorder buffer, rename buffer. They extract hidden parallelism out of the code, run it in blazing fast multiple instructions per cloc…

The designs are smart. The CPUs themselves are still dumb, which is precisely the reason why speculative execution bugs exist. It's magic up until the point all the tricks spill out. In the end, it's always just logic gates wired together to do certain things — whether it's a Z80 or an M2 Max. All this layered complexity is simply the product of 50 years of iterative improvements.
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