I want to thank you ko888 as well. I have the same mobo and M4 setup. I was having trouble getting my firmware to update on the M4. During post, my drives weren't even showing up. I found this post and swapped the ports. Firmware updated like a charm
Well, it turns out that you cannot updgrade your firmware at all with the drive plugged into the Marvel controller, at least I was unable to, even with a boot disk.
I want to show you what a difference it made in the performance of my drive: