I have a GA-965P-DQ6 with the ICH8R. I just created a RAID 5 array with 4 1TB drives. I first created the raid 5 array @ 2TB in the BIOS fine.
In Windows I created a GPT partition on the drive. Using the Intel Matrix Storage Manager I increased the array size to 100% capacity. I started getting failures and the IMSM started kicking off "verify and fix" on the array automatically. Then my explorer started hanging on writes.
I destroyed the array and ran CHKDSK on the disks individually and they were fine.