I've used raidframe for years now up to 1.6.2. It worked for me
quite well -
  - about 60-80% performance boost for a simple two-disk stripe,
  - about 80% performance of the single disk for a simple mirror.
(both are raw, sequential reads/writes)

now, I tried 2.0-RC5. unfortunately something is very wrong there :(

raw sequential access looks fair, but random-access is horrible.
newfs'ing a 65 GB partition takes about 5 minutes (bs=8192,
fragment=1024) it's about 35-45 seconds on the same hardware w/1.6.2.

the fs then mounts okay, but copying files onto it takes forever,
and while it's copying, the box locks up, sometimes even pinging the
machine, or get into the CRTL-ALT-ESC debugger is impossible.

raidframe or other sw raid solution is mission-critical for me, any help
is greatly appretiated.

reproduced this on several machines, including HP/Compaq Proliant
ML370/onboard SCSI/72GB disks and simple desktops. dmesg outputs
are available, if needed.

on the other side, i386 SMP support is very impressive! guys, keep
up the good work! but for now, please fix raidframe before 2.0
hits the markets :)

simple mirror config:

START array
1 2 0

START disks
/dev/sd1e
/dev/sd2e

START layout
128 1 1 1

START queue
fifo 100

-- 
Gergely EGERVARY
Network Administrator