Comment by vardump

The first thing a 4k demo is going to do is to decompress executable. The second thing is to procedurally generate assets. Perhaps also do some code generation. So the cache footprint is going to be larger.

At this point you can be talking about 600 kB on a DOS machine. Sky is the limit on modern systems.

That said, typical inner loops of that era demos were pretty small, usually 20-200 byte range, IIRC.

Pre-cache era demos often had huge unrolled self-modifying speedcode inner loops, but that's another matter.