There is a use case when you can improve performance by keeping compressed (LZ4) data in RAM and decompressing by small blocks that fit in cache. This is demonstrated by ClickHouse[1][2] - the whole data processing after decompression fits in cache, and compression saves the RAM bandwidth.
You're correct but that is still a niche segment because markets that need 128MB of super-fast memory are almost always happy to pay a little bit more to get 4GB+ of "L4" (aka DRAM).
The economic point stands that you aren't going to get a processor with only cache and no RAM because virtually no workloads want such an unbalanced system.
As SSDs get faster and L3 caches get larger, will conventional RAM get squeezed out? I know Optane failed a few years back, but that kind of convergence seems inevitable in the long term.
There is a use case when you can improve performance by keeping compressed (LZ4) data in RAM and decompressing by small blocks that fit in cache. This is demonstrated by ClickHouse[1][2] - the whole data processing after decompression fits in cache, and compression saves the RAM bandwidth.
[1] https://presentations.clickhouse.com/meetup53/optimizations/ [2] https://github.com/ClickHouse/ClickHouse