SAS controller for FreeBSD

[Daniel Feenberg]

We have been using ZFS under FreeBSD for a while, and are very pleased, 
but are considering building a system with SAS drives, in the hope that 
they will be faster (any truth to that?). I am assuming that I should look 
for a non-RAID controller, but I can't find any SAS controllers that don't 
claim to do RAID and are on the FreeBSD compatibility list. I have always 
thought that using a RAID controller for a non-raid partition was a bad 
idea, since it limited ones ability to swap controllersm, and presumably 
if we are using ZFS for our RAID we don't need another level of RAID 
provided by the controller. Is that prejudice justified?

There are some SAS RAID controllers that claim to support FreeBSD but I 
can't tell if their JBOD mode is a true pass-through, or leaves some 
undesirable junk on the disk.

So does anyone have a recomendation for a reasonably priced SAS 
controller? We aren't looking for anything fancy at this point.

Daniel Feenberg
NBER