Curtis, have you considered comparing raw writes versus file system writes
on a raw multi-disk partition?
I always set up my machines to store data on a mirror set (RAID1) or RAID5
set, and it seems your method should be tested there too.
P.s., Tom, the postgresql user would NOT need to run as root to do this,
you can just do a 'chown postgres.postgres /dev/sda1' or 'chown
postgres.postgres /dev/md0' to give postgresql permission to write / read
from a raw partition.
That said, I am not sure how much we are likely to gain from this method
either. But if no one tries it out we'll never know.