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Unlike marketing terms, "nm density" is actually useful measure. It describes density measure where you can compare it to planar transistors from the 28-nanome
by u1hcw9nx 4mo ago
Unlike marketing terms, "nm density" is actually useful measure.
It describes density measure where you can compare it to planar transistors from the 28-nanometer (28 nm) node around 2010 to 2011 and before. A "0.7 nm" node has equivalent transistor density as if we could have shrunk standard flat transistor node down to 0.7 nanometers.
- measurablefunc 4mo agoDensity is mass per volume so how are you comparing it to a planar transistor? Your units don't even match.
- bronson 4mo agohttps://en.wikipedia.org/wiki/Transistor_count#Transistor_density https://en.wikipedia.org/wiki/Transistor_count#Transistor_de...
- gruez 4mo agoNot all densities is mass per volume. eg. population density.
- measurablefunc 4mo agoIt's a physical quantity per some unit of spatial measurement so the units still don't match up b/c in one case the transistors are stacked per volume & in the other case per area. > Historically, "node" sizes (like 28nm or 7nm) directly correlated to the physical length of a transistor's gate. Today, names like 3nm or 2nm reflect a marketing generation. The actual transistors are significantly larger than these nanometer labels, meaning density varies between companies > Research organizations like IEEE have proposed new metrics, such as transistors per cubic millimeter (MTr/mm^3), to accurately map future 3D scaling. However, commercial chip foundries resist this change because it would make it harder to calculate commercial yields and thermal density limits using standard industry formulas. https://share.google/aimode/Z5BqUjlZWFNphm6Z6 https://share.google/aimode/Z5BqUjlZWFNphm6Z6
- formerly_proven 4mo ago> It's a physical quantity per some unit of spatial measurement so the units still don't match up b/c in one case the transistors are stacked per volume & in the other case per area. "Planar" and "3D" in this context refers to the shape of the transistors themselves. In a planar transistor the functional structure is spread out in the area, like this: https://en.wikipedia.org/wiki/File:MOSFET_functioning_body.svg https://en.wikipedia.org/wiki/File:MOSFET_functioning_body.s... while 3D transistors spread into the volume: https://en.wikipedia.org/wiki/Multigate_device#/media/File:Doublegate_FinFET-en.svg https://en.wikipedia.org/wiki/Multigate_device#/media/File:D... However the active devices are still just one layer. This isn't like 3D NAND where you actually have transistors on top of each other. So the comparison only considers the area for both kinds of transistors.
- measurablefunc 4mo ago[flagged]
- roetlich 4mo agoWell, this seems like a very dangerous way of using AI. If you keep pushing until you get back an answer that makes sense to you, you might just get your own believes fed back to you.
- measurablefunc 4mo ago[flagged]
- sbergot 4mo agoThe comparison is good. Humans are also stacked in volumes and we still measure population density over a surface because the third dimension is less significant in this context.
- measurablefunc 4mo ago
- zmgsabst 4mo agoPopulation density isn’t planar, eg, why cities are denser than towns: their centers are more than 2D.
- short_sells_poo 4mo agoPopulation density is literally measured over a planar metric: people/km^2 You are suggesting it's measured over a cube volume?
- jonsen 4mo agoThere are some really dense people
- rycomb 4mo agoSome people are dense... now in three dimensions!
- dodslaser 4mo ago3d population density would be an interesting measure, though. It would provide a better feel for how cramped a populated volume actually is. It would have to be the displacement volume, to account for cities with only a few really tall buildings, and also somehow adjusted for buildings with high ceilings.
- john_strinlai 4mo agodensity is quantity per unit measure. mass per volume is one example.
- amirhirsch 4mo agoDensity is this reply.
- bandrami 4mo agoAll "density" means is that it's a quotient; I use spectral densities daily and that's "count per Hertz" which weirdly enough works out in normal units to be seconds.
- deleted 4mo ago[deleted]
- jayd16 4mo agoWhy not use something absolute, like nand-gates per volume?
- mikepurvis 4mo agoI am not a chip designer, doesn't area matter way more than volume? Vertical space is basically free; it's horizontal space that is at a huge premium.
- Intralexical 4mo agoPlus heat dissipation is a limiting factor, which scales with area.
- u1hcw9nx 4mo agoTransistor density in units of MTr/mm. (Million Transistors per square mm) is also used. The formula is MTr/mm = 0.6×(NAND2 Tr Count)/(NAND2 Cell Area) + 0.4×(Scan Flip Flop Tr Count)/(Scan Flip Flop Cell Area)
- jayd16 4mo agoWhy do you think it's not commonly used?
- Smalltalker-80 4mo agoYeah, the actual sizes are right there in the pictures, and never < 1 nm.
- YetAnotherNick 4mo agoWhy is density any bit important? All I care about is the price per transistor, and the power usage(mostly gate charge and leakage current?).
- myrmidon 4mo agoDensity does directly scale with both of those in the form of more chips per die (=> lower cost) and smaller capacitance (=> less dynamic power dissipation). If you want to reduce "effectiveness" of some process down to a single number, then density is far from the worst metric to pick.
- jhide 4mo agoWhy is that all you care about? Stepping down a node gets you dramatically improved timing and design feasibility. The reduced density means you can pack the same design into less area. Your most challenging timing paths now have to traverse a shorter distance, and you can fit more of them relative to certain node-size invariant structures
- u1hcw9nx 4mo ago[flagged]
- sbergot 4mo agoisn't density a way to lower both the price and energy dissipation (so better heat management & energy efficiency)?