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0 pointsverall5y ago0 comments

> The thing that's gotten smaller is the minimum feature size on a silicon wafer.

No, even minimum feature size is improving much slower than in the past. Fabs are focusing on specifics that are still giving gain: lower power transistors, SRAM. Really high performance transistors like for amps have not gotten much smaller, DRAM has not gotten much smaller, analog has not gotten much smaller.

The capacitors and sense amplifiers in DRAM have not gotten smaller nearly as fast as any of the other features.

> DRAM chips are integrated circuts that consist of individual transistors and capacitors for each bit, plus the wiring and logic to read, refresh, and write to those bits.

I know what a DRAM is...

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klodolph5y ago

That’s a very satisfying answer. I’m aware that the processes for logic, flash, and DRAM have some significant differences but I don’t know much more than “differences exist” (e.g. and therefore you have a different die for CPU and flash).

My reasoning is, at best, “SSDs have gotten cheaper, SSDs are kind of like RAM, shouldn’t RAM get cheaper?” and I know that’s not exactly an expert opinion.

sroussey5y ago

SSDs are non-volatile — they don’t need power and constant refreshing like DRAM does. So you can do different things based on a different heat and power budget, like going 3D and adding more layers that would kill regular ram or a cpu, etc.

wmf5y ago

NAND flash went from one layer to 128 layers over the last decade while DRAM is still one layer.

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