UPDATE #2:
So I went to burn a DVD yesterday and got all sorts of errors and slowness. As I mentioned previously, I put my optical drives on the Marvell controller (ports SATA3_6 and SATA3_7). Given the errors, I uninstalled the hardware, restarted PC, and allowed Windows to install the generic drivers. I also changed the controller back to IDE mode.
These changes yielded no improvement so I moved the optical drives to the Gigabyte controller (ports SATA2_8 and SATA2_9) and all is well.
Man, I almost think there should have been a recall on these Marvell chips.