Mark, On 2/24/06 10:10 PM, "Mark Kirkwood" <markir@xxxxxxxxxxxxxxx> wrote: > Well, since this is always fun (2G memory, 3Ware 7506, 4xPATA), writing: > > $ dd if=/dev/zero of=/data0/dump/bigfile bs=8k count=500000 > 500000 records in > 500000 records out > 4096000000 bytes transferred in 32.619208 secs (125570185 bytes/sec) > Reading: > > $ dd of=/dev/null if=/data0/dump/bigfile bs=8k count=500000 > 500000 records in > 500000 records out > 4096000000 bytes transferred in 24.067298 secs (170189442 bytes/sec) Not bad at all! I have one of these cards in my home machine running WinXP and it's not nearly this fast. > Hmmm - a bit humbled by Luke's machinery :-), however, mine is probably > competitive on (MB/s)/$.... Not sure - the machines I cite are about $10K each. The machine you tested was probably about $1500 a few years ago (my guess), and with a 5:1 ratio in speed versus about a 6:1 ratio in price, we're not too far off in MB/s/$ after all :-) > It would be interesting to see what Dan's system would do on a purely > sequential workload - as 40-50MB of purely random IO is high. Yeah - that is really high if the I/O is really random. I'd normally expect maybe 500-600 iops / second and if each IO is 8KB, that would be 4MB/s. The I/O is probably not really completely random, or it's random over cachable bits of the occupied disk area. - Luke
