While waiting for a 22GB text file to be read through a filter, I was
just wondering whether I should expect a faster read rate..

 88% |********************************     | 19885 MB    4.06 MB/s    10:49 ETA

is what progress says, so as the disks aren't doing anything else, is that
a reasonable way to estimate read speed? But then, what does iostat
tell me?

% iostat sd2
      tty              sd2             CPU
 tin tout  KB/t  t/s  MB/s  us ni sy in id
   0   76 30.83   31  0.92  18 70 12  0  0
% iostat -I sd2
      tty              sd2             CPU
 tin tout  KB/t  xfr  MB    us ni sy in id
113242 25842236 30.84 10380986 312630.71  18 70 12  0  0

and the hardware is

mpt0 at pci2 dev 3 function 0: LSI Logic 53c1030 Ultra320 SCSI
mpt0: interrupting at irq 10
scsibus1 at mpt0: 16 targets, 8 luns per target
sd2 at scsibus2 target 0 lun 0: <LSILOGIC, RAID ARRAY    IS, 1000> disk fixed
sd2: fabricating a geometry
sd2: 136 GB, 139712 cyl, 64 head, 32 sec, 512 bytes/sect x 286130176 sectors
sd2: sync (6.25ns offset 127), 16-bit (320.000MB/s) transfers, tagged queueing
sd2: fabricating a geometry
sd2: fabricating a geometry

two scsi drives striped by the lsilogic controller, so appearing as 1 disk.
(320MB/s just seems like a bigger number than in the above stats)

Thoughts?

Cheers,

Patrick
(running 3.99.3/i386 of 25 April)