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r2k-in-the-vortex t1_j265wfw wrote

Reply to comment by HashedEgg in TSMC starts volume production of 3nm chips by filosoful

Silicon crystal structure is like so, therefore 3nm is 5.5 repeating units long. There is no feature this small in a transistor. I don't know the figures for TSMC 3nm, but for 5nm Samsung 5LLP process the fin pitch is 27nm. That's the smallest dimension in the transistor. How it translates to 5nm is a matter of history and marketing.

With plain old planar process it was a straightforward matter, make the transistor smaller you make it faster and more energy efficient. So that's where using the nanometers came from. That ran up against the wall at about 32nm. The next innovation from that was finfets, which is a different way to construct a transistor and make it more energy efficient and faster.

But it's still the same size, how are you going to sell it to consumer than is used to buying nanometers? You fib it a little and say, if with planar technology we made a transistor 14nm size, then it would be as fast and energy efficient as this transistor right here. And that's what the nanometers are these days, they are not actual dimensions anymore.

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HashedEgg t1_j2673iq wrote

Aaah that makes waaay more sense, thanks! So basically all the terminology bs we have in computer hardware goes down to component level... Marketing terms can be so annoying...

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r2k-in-the-vortex t1_j26a30w wrote

Just wait until you learn about camera sensors.

Reality is that customer buys a functionality and really only very superficially cares about how things are built or why they are built a certain way. That's how you get these sorts of pseudo specs that are really just marketing terms.

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paint-roller t1_j26q4ss wrote

Unless using cameras is your job no one other than the engineers who make or services cameras/sensors/lenses needs to know this stuff....actually I doubt most people who operate cameras for a living know that 2/3, 1/2, 1/3 inch sensors get their classification based off of old imaging tunes.

It is pretty interesting though.

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SaintsNoah t1_j27j9yz wrote

Thank you for explaining this. I've read many times that "the numbers dont mean anything" but the way you explain it is far from arbitrary. Sounds like the concept of measuring cars in Horsepower

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r2k-in-the-vortex t1_j282a2w wrote

Pretty much, it's a comparison to legacy that has lost it's meaning.

The only comparison that really matters is functional comparison to one generation before - "Liu said TSMC's 3nm technology would feature an estimated 60 percent gain in density of logic transistors and reduce power consumption by 30 percent to 35 percent at the same rate compared with 5nm technology."

That's real deal. But the 5nm and 3nm classification, that's marketing term that has lost it's meaning.

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Auberginebabaganoush t1_j2746xp wrote

So. To be clear. The smallest actually measurable component is around 27 nm, and saying 3 or 5nm is just saying that this is the equivalent efficiency of a planar transistor?

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TerpenesByMS t1_j29v5sm wrote

So it IS a fib based in marketing! Thank you for the enlightenment!

This makes sense, with the marketing being "equivalent to theoretical planar transistors of X nm".

So, if I infer correctly, tunneling is still a technical wall of sorts, and the game is more about optimizing actual logic gate and circuit design more than simply shrinking components like it used to be?

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r2k-in-the-vortex t1_j2b143d wrote

Yeah, finfets and ongoing transition to gate all around fets is basically more efficient, but geometrically more complicated ways to build a transistor.

Don't get me wrong, the components are still shrinking, EUV rollout has been a gamechanger for that. But that shrinking doesn't keep pace with nanometer node numbers anymore because modern transistors are just not the same as planar process transistors were.

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