[lug] SW Raid question

[dio2002 at indra.com]

I just purchased a new SuperMicro system with an onboard 4 port SATA ICHR7
adaptec controller.  SM does have source code for this controller but it
is fakeraid.

I bought the system with the intent of disabling the raid support on the
controller so that i could run mdadm SW raid on it.  However, now that i
have the system, i've found out that disabling the raid support on the
bios puts that sata controller in "compatibility" mode, which means that
it drops to ATA 100 speed.  wtf!  shouldn't this be able to operate in
some kind of "std" SATA mode?  that's a pretty big drop down in
performance.

i'm puzzled at my options right now.

1) I can download that fakeraid driver

however, i've heard they're slower than sw raid and prone to boot failures
when the one drive goes down.  then there's the whole issue of compiling
the thing and making the install recognize that driver at CentOS 5 install
time.  Not sure how to do that, if it's even a loadable module or if the
installed kernel will pick up that driver after install for future boots? 
Then assuming i have to upgrade my kernel's in the future, i'd prefer to
be able to do straight rpms rather than kernel rebuilds.  This route seems
to increase my admin load at the expense of a rather poor solution to
begin with (at least from what others have said)

2) I can disable bios raid and go with sw raid like initially intended

seems like the simplest.  but that drop in performance has me concerned. 
and not being a hw guru, i'm imagining that the hds still operate on
separate channels (so no contention) on the SATA controller at 100MB
eventhough they are put in "compatibility" mode.  i guess i'm asking if
there is more of a performance hit than just the pure speed with this mode
that i'm unaware of.

3) i can buy a true raid hw card

recent posts raved about hw raid.  but it's more money, i don't really
need that extra performance when sw raid would be fine and most
importantly i'm not sure about support for CentOS 5.  If i go this route,
i'd like to be able to buy a SUPPORTED card FOR MY RELEASE quickly without
a 21 day search to find the answer and then install it without hopefully
having to do a lot of install / kernel / driver / boot wrangling to get
this thing working, but something tells me i'm looking at similar driver
compiles as spec'd in #1.

If there was a HOWTO on this route, i'd be more apt to go it.  The tricky
part for me is that the non stock driver needs to be available at install
time.  Normally, you already have a running system with which to build the
driver and or kernel.  I have neither in this case.  It's sort of a catch
22.

Anybody care to help out with a few suggestions/recommendations/tips.