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SRAM has really stalled. I don’t think 5nm was much better than 7nm. On ever smaller nodes, sram will be taking up a larger and larger percent of the entire chi

SRAM has really stalled. I don’t think 5nm was much better than 7nm. On ever smaller nodes, sram will be taking up a larger and larger percent of the entire chip. But the cost is much higher on the smaller nodes even if the performance is not better. I can see why AMD started putting the SRAM on top.

magicalhippo 2y ago
It wasn't immediately clear to me why SRAM wouldn't scale like logic. This[1] article and this[2] paper sheds some light. From what I can gather the key aspects are that decreased feature sizes lead to more variability between transistors, but also to less margin between on-state and off-state. Thus a kind of double-whammy. In logic circuits you're constantly overwriting with new values regardless of what was already there, so they're not as sensitive to this, while the entire point of a memory circuit is to reliably keep values around. Alternate transistor designs such as FinFET, Gate-all-around and such can provide mitigation of some of this, say by reducing transistor-to-transistor variability by a factor, but can't get around root issue. [1]: https://semiengineering.com/sram-scaling-issues-and-what-comes-next/ https://semiengineering.com/sram-scaling-issues-and-what-com... [2]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9416021/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9416021/