since modern disks can read a whole track at once, there's no "reload" time. it would only make sense to interleave you have more than 1 i/o process (venti seems to have a few) and you're either running faster than the disk bandwidth. the disk bandwidth could be as high as 60MB/s for sequential reads and as low as 1MB/s for small reads with many seeks.
if most of venti's io is via the read ahead process, i think there would be very limited benefit by interleaving i/o. and you would need four disks. if you use two disks partitioned in ½, you will insure that every write will generate a huge seek. - erik
