Willy Tarreau wrote:

I like it. It's fairly simple. I'm always amazed how many people do really
believe that these cards provide hardware RAID !!! The problem is when you
ask a reseller to add a real hardware RAID card in a system you purchase
and you end up with a cheap silicon image... It happened to us once and it's
not funny at all.

On the brightside, md raid5 is often faster than hardware raid5.  At 
least on the 7000 and 8000 series of 3ware hardware; the 9000 series 
looks promising though.  I haven't seen megaraid SATA numbers, and I 
don't know what happened to the SX8.

When the libata Marvell drivers come out, you'll have a cheap upgrade 
path for PCI-X boards if you want fast md raid: 
http://www.supermicro.com/products/accessories/addon/DAC-SATA-MV8.cfm  
$100 to add 8 unbottlenecked SATA ports to your server motherboard.

-ryan