OK. I have a new build using a Gigabyte MOBO and it has 6 ports on the ICH9R and 2 on the Gigabyte chip set. I created my boot drives using RAID 1 on the ICH9R and things are working fine. Performance isn't great but it's fine for loading apps as I use other drives for scratch dick space.
I was thinking about making one of my data drives RAID as well. I've been using Retrospect to do daily backups for years and it works great. It basically just make a copy of the data drive to a matching disk.
If I do make this a RAID drive I know that performance will drop about 15% but I was curious if it's best to have 2 separate RAID volumes on the ICH9R or 1 on the ICH9R and one using the Gigabyte chip set.
The GigaRaid ports are on the same bus as the PCI & network port(s). How much data is going down that channel will have an effect on your throughput. <--- I don't know if that will be material however!
I would put both on the ICH9R so I don't have to worry about two different interfaces (BIOS) to manage the disk arrays, two different disk searches when starting up, and two different software tools to manage/monitor the arrays from Windoze.