Looks like magic
How to make a CPU – a simple picture-based explanation
21–30 of 176 posts
Re: How to make a CPU – a simple picture-based explanation
#22I've always been curious how someone gets into this line of work. Is it all via college / post education and your directly recruited by these companies? Obviously, this is a very hard (impossible?) thing to teach yourself. I can't imagine more than a few universities offer this type of education? Where would you start / what path would you go down to be a chip designer / work for an Intel / AMD ???
I got my electrical and computer engineering (ECE) degree in 1999 from UIUC and learned everything but the very lowest-level chemistry, because I specialized in the VLSI (circuit design) side instead of fab. At that point, stuff like MIPS and the DEC Alpha were popular, and computers were just breaking the 1 GHz barrier. Unfortunately the dot bomb happened right after I graduated, and the anti-intellectual backlash o…
>Only Apple with their M1 seems to have any will to venture outside of the status quo
I find this an interesting opinion considering that the M1 is really just "The same, but a bit larger" - IE slightly higher performance at a higher cost.
What exactly do you see with the M1 that makes it so different?
Re: How to make a CPU – a simple picture-based explanation
#23I've always been curious how someone gets into this line of work. Is it all via college / post education and your directly recruited by these companies? Obviously, this is a very hard (impossible?) thing to teach yourself. I can't imagine more than a few universities offer this type of education? Where would you start / what path would you go down to be a chip designer / work for an Intel / AMD ???
I got my electrical and computer engineering (ECE) degree in 1999 from UIUC and learned everything but the very lowest-level chemistry, because I specialized in the VLSI (circuit design) side instead of fab. At that point, stuff like MIPS and the DEC Alpha were popular, and computers were just breaking the 1 GHz barrier. Unfortunately the dot bomb happened right after I graduated, and the anti-intellectual backlash o…
> Meanwhile we're stuck with SIMD now instead of MIMD…
What about multi-core/multi-threading combined with massively out of order CPUs? Intel and AMD’s chips have a dozen or so execution ports. So you can have your PADD running on one port, and a PMUL on another. It just happens all being the scenes.
Intel tried a VLIW architecture with Itanium, but it was a flop for a variety of reasons. One of which was the lack of “sufficiently smart compilers”. There’s also the benefit to all the nuances of execution being in hardware: programs benefit from new CPUs without having to be recompiled. It has a much more intimate knowledge of how things are going than the software does (or even the compiler).
Re: How to make a CPU – a simple picture-based explanation
#24Circuit designer here - feel free to ask any questions about the manufacturing process, design etc.
Having a thorough understanding of the process, I thought this was hilarious. But if you really want to understand the process, it's pretty terrible. It spends 10 steps on making a wafer, and then the bulk of the actual process is condensed to 16.
Re: How to make a CPU – a simple picture-based explanation
#25Nice illustrations, though step 16 is pretty much "Draw the rest of the F** owl."
I'm pretty sure producing the monocrystalline ingot with seven 9's purity also counts as the "rest of the owl", along with basically every other step in this guide. I'm not even convinced that the sawing step is simple – thermal stresses, limitations, impurities, tool hardness and dimensional accuracy concerns, minimising material losses, etc. (I loved his butter knife).
The knife was a great touch! It did look like he was lining it up carefully...
Also, it took me two passes through to notice the tooth brush in step 16.
Re: How to make a CPU – a simple picture-based explanation
#26Circuit designer here - feel free to ask any questions about the manufacturing process, design etc. Having a thorough understanding of the process, I thought this was hilarious. But if you really want to understand the process, it's pretty terrible. It spends 10 steps on making a wafer, and then the bulk of the actual process is condensed to 16.
Not what you were offering so feel free to ignore this, but I'm super curious about RISC-V. Do you know if any serious attempts are happening to make RISC-V based systems? And if not, do you know why? Is it too raw/un-polished?
Re: How to make a CPU – a simple picture-based explanation
#27I've always been curious how someone gets into this line of work. Is it all via college / post education and your directly recruited by these companies? Obviously, this is a very hard (impossible?) thing to teach yourself. I can't imagine more than a few universities offer this type of education? Where would you start / what path would you go down to be a chip designer / work for an Intel / AMD ???
I studied computer engineering (EE/CS) from 1996-2001. My senior year the college offered a minor in VLSI design, it was a 4 course series covering the very basics of semiconductor design and test and as one of the projects we actually paired up and designed a small chip, here's a photo of the finished die. Simple 2-layer metal 1 micron process - this is a serial multiplier for two sixteen-bit integers. https://vazor.com/drop/mulman.jpg
Most of the students in these classes were graduate students, so with our normal course load as seniors in engineering, this was a tremendous effort. For a four-credit class I would sometimes have to work 20+ hours a week just on one class.
But, it was a good stepping stone to get into the industry - my first job was at LSI Logic executing physical design, timing closure, etc for their customers. I learned a lot but eventually stepped away from it to focus on software and startups - I didn't want to die at that desk - the designs and teams were getting bigger and the design cycles longer. I did not relish the idea of working for 3 years on a single project.
I do look back on it fondly though as it was closer to what I consider 'real' engineering - we did a ton of verification work and if you screwed up, it might be a million in mask costs and 3 months of time to fix. We did screw up from time to time and the customer often had some fixes, so on a new design, there were expected to be a couple iterations of prototypes before you went to production. I think the last design I taped out was in the 110nm node - ancient by today's standards.
Re: How to make a CPU – a simple picture-based explanation
#28As a film photography enthusiast, I love the parallels between making a chip and film development. I wonder if film developing was the original inspiration
Direct ancestor probably is mask-and-tape PCB design process, where the optical step also serve to shrink the (hand made) mask to significantly smaller size of the final board. In fact silicon masks were for a long time designed using essentially same process.
In fact if you want to make something mostly flat with small features some variation of photo etching process tends to be the easiest and most repeatable way to go about that.
Re: How to make a CPU – a simple picture-based explanation
#29I recall there being a game mentioned somewhere here on HN, where you start with basic logic gates (I think), and you build up a fundamental CPU at the end of the game, using the parts you discovered along the way.
Problem is, I don't remember what the game is called, and no amount of searching seems to help me. Anyone know what it was called?
Re: How to make a CPU – a simple picture-based explanation
#30The hilarity illustrates an important point. We never just make a thing. A recipe or blueprint is a convenient fiction. Rather we participate in a dynamic evolving process which itself evolved through many cycles of copying, repetition and debugging. Even the first version wasn't strictly original because the idea was borrowed from elsewhere. 'Oh you work at the olive press. How would you like a job with this new-fangled printing machine?' And so on back to the initial and highly controversial creation of the Universe.