Hi there kingjezdi. Interesting that you're reading up on UDMA66. That's old school technology that's no longer in use on our brand new pc's.
UDMA66 was a cachebuffer technology for the IDE interface of old HDDs and CDROMs supporting transferrates of up to 66MBps. Todays SATA standard has transfer rates of 600MBps on the SATA3 interface and 300MBps on the SATA2 interface. Your computer uses both these interfaces with SATA3 for the SSD and SATA2 for the HDD. The computer also supports M.2 PCIe 4x SSDs that can reach over 1GBps on the newest modules. So, as you can see UDMA66 is a 1990's technology that is no longer in use and there in no way, nor any reason to have it activated on your computer. The technology is so old in fact that it might not be supported by Windows 8 anymore, Windows XP being the last MS OS that supported the technology.