Software raid5 through a sata port multiplier

[Maxim Khitrov]

Hello all,

I'm building a file server that must use an external sata hard drive
enclosure. It will begin with 3 2TB (RE4-GP) hard drives and expand as
needed. I've looked at 3ware and Areca hardware raid controllers with
external sata/sas ports and currently have some doubts of whether the
cost can justify the performance. This is also an addition of yet
another piece of hardware that can fail.

The machine is using a Q6600 processor with 8 GB of memory, so I'm
thinking that a software raid5 solution may not be such a bad idea.
The question is what port multiplier hardware does FreeBSD 7 support?
I found an 8-bay rosewill enclosure that claims to use
Sil3726/Sil3132R5 controllers. Is there a driver that supports these,
and if so, what throughput can I expect from this setup (compared to
hardware raid alternatives)?

- Max