I have used the P35-DQ6 and RAID, and several times have had RAID arrays fail on both the P35-DQ6 and EP35-DS4 boards that I tested. One was a RAID 10 array, the other a RAID 0. In the case of the RAID 10 array I was preforming a warm reboot, I rebooted, and suddenly the AHCI RAID controller could not detect the RAID array and said two of the drives had failed. Didn't matter if I reset the system back to stock, or replaced the motherboard with the DS4 but it couldn't find the array.

After that I started testing, and began noticing that even mild overclocks of ~3.2GHz on my Q6600 would start to see bad data written to the RAID array. For awhile I thought it could be anything from a unstable overclock to unstable RAM, but it wasn't. Have you run the hard drive array data verification & repair test under Intel's Matrix Storage controller? It was finding anywhere from 10-100 errors every few days... Worried about my RAID array I reset to stock but then even at stock it started finding errors! Those were also Seagate hard drives, four 7200.10 320GB drives.

After losing a second array and getting nothing but new data verification errors on a 3rd RAID array I gave up Intel Matrix RAID, it offers no protection whatsoever and all it takes is a single reboot to go from a fully working RAID 10 array to losing all your data. Much safer to buy a NAS with RAID, use just a single drive for overclocked systems or an SSD. Much fewer headaches, frustration, and risk that way.