It's probably having a mix of 1KB and 4KB that's slowing you down. I
use 4KB block file systems exclusively because my tests show them
performing better than 1KB file systems, and I have more disk space
to waste than CPU cycles.
I haven't checked the buffer cache code lately, but in the past it
didn't deal well with having a mix of differently sized buffers.
It should be possible to make 1kb filesystem to have nearly all of the
performance advantages of the 4kb filesystems, while still retaining
their disk space efficiency advantages. That isn't the case today, but
hopefully we can fix that.
- Ted