2 things come to mind. Less overall overhead associated with the dir. cache
(less code overall) and I'm thinking that the dir. cache itself might be small
enough to fit within a motherboard L2 cache, whereas the buffer cache is
allocated as needed = spread out thruout your memory.
The dir cache is allocated in one big lump sum, basically.
I found it all pretty interesting.
--- Which is worse: ignorance or apathy? Who knows? Who cares? Life is sexually transmitted. Disco is to music what Etch-A-Sketch is to art.