Quote from gnome:
The proper question should probably be, "does RAID 0 improve trading performance"... probably not for most except possibly those who view themselves as uber scalpers. (And 99.999% of them guys are totally delusional.)
gnome is correct, almost no one needs it, and it does greatly increase your chance of complete loss of data.
That said, I run Raid 0 w/15k SAS drives on my colocated boxes, I'm running my trading app and databasing full tick on L1 & L2 data (all books), as well as heavy application logging. This is several GB of data a day. Raid 0 has definately been a big help
in keeping this running smoothly.
I've done this on non raid 0 drives, and got a high frequency of
'delayed drive write' errors, where the disk couldn't keep up.