Earlier quoted context omitted.
I saw that point brought up on Twitter and I don't know how it it makes more efficient use of RAM. Specifically, as I understood it is that Apple software (written in objective C/Swift) uses a lot of retain/release (or Atomic Reference Counting) on top of manual memory, for memory management rather than other forms of garbage collection (such as those found in Java/C#), which gives Objective C programs a lower memory…
The only thing I can think of that would actually reduce memory usage on M1 vs the same version of MacOS on x86 would be if they were able to tune their compressed memory feature to run faster (with higher compression ratio) on the M1. That would serve to reduce effective memory usage or need to fall back to swap. I would not expect something like that to be responsible for more than, say, a 5-10% RAM usage decrease…
I think you can reach a lot more than that. Presumably, on Intel they use something like LZO or LZ4, since it compresses/decompresses without too much CPU overhead. But if you have dedicated hardware for something like e.g. Brotli or zstd, one could reach much higher compression ratios.
Of course, this is assuming that memory can be compressed well, but I think this is true in many cases. E.g. when selecting one of the program/library files in the squash benchmarks:
https://quixdb.github.io/squash-benchmark/
you can observe higher compression ratios for e.g. Brotli/gzip/deflate than LZO/LZ4.