That is interesting. I wonder if L1 is denser because it has to have more bandwidth. But doesn't that point to a space constraint rather than money? A combination of L1 & L2 will have a bigger capacity so it would be faster than pure L1 cache in the same space (for some/most workloads)?
I always thought cache layers was because of locality but that is my imagination :) The article talks about different access patterns of the cache layers which makes sense in my mind.
It also mentions density briefly:
> Only what misses L1 needs to be passed on to higher cache levels, which don’t need to be nearly as fast, nor have as much bandwidth. They can worry more about power efficiency and density instead.
I always thought cache layers was because of locality but that is my imagination :) The article talks about different access patterns of the cache layers which makes sense in my mind.
It also mentions density briefly:
> Only what misses L1 needs to be passed on to higher cache levels, which don’t need to be nearly as fast, nor have as much bandwidth. They can worry more about power efficiency and density instead.