It's true we hit limits, but I feel like a lot of it was "limits" in the sense that the tradeoff stopped being worth the cost, so we optimized in other areas.

So we hit limits on clock speed in the early 2000s (ex - the 4ghz wall) but it also turned out that mobile as the driver for sales meant no one really cared much about clock speed compared to performance/watt.

Clock speed mattered, but only relative to how many watts it took to get it (and above 4ghz... too many watts).

But we've seen a 15x improvement over the last 20 years. Performance/Watt is WAY up.

My guess is that LLMs are going to drive another "improvement cycle" in areas that we didn't care much about before.

I've built about 10 personal desktop machines (1 every ~4 years) and I can honestly say that I didn't care much about memory bandwidth prior to 2021.

In the same way that I didn't care much about how many watts my pentium 4 was using in 2005.

But now... now I care a lot about memory bandwidth. I care about memory speeds and total system ram in a manner I really, really didn't before.

So I think we're going to see a big shift to machines built on unified ram with a crazy focus on squeezing memory bandwidth and total ram capacity as far as we can.

My bet is that we'll get a similar 10-15x improvement by 2040 in unified system ram designs.

I fully expect to see 2tb unified ram desktops and 200gb unified ram phones be relatively common on a 20 year timeline, assuming we see similar levels of geopolitical stability (ex - world war 3 throws a wrench into things).