Peter, On 1/9/06 12:59 PM, "peter royal" <peter.royal@xxxxxxxxx> wrote: > Overall, I got a 50% boost in the overall speed of my test suite by > using XFS and the 16k read-ahead. Yes, it all looks pretty good for your config, though it looks like you might be adapter limited with the Areca - you should have seen a read time with XFS of about 17 seconds. OTOH - with RAID5, you are probably about balanced, you should see a read time of about 19 seconds and instead you'll get your 22 which isn't too big of a deal. > Thanks for the help! Sure - no problem! BTW - I'm running tests right now with the 3Ware 9550SX controllers. Two of them on one machine running simultaneously with 16 drives and we're getting 800MB/s sustained read times. That's a 32GB file read in 40 seconds (!!) At that rate, we're only about 3x slower than memory access (practically limited at around 2GB/s even though the system bus peak is 10GB/s). So, the point is, if you want to get close to your "warm" speed, you need to get your disk I/O as close to main memory speed as you can. With parallel I/O you can do that (see Bizgres MPP for more). - Luke
