Hi all,
Just wanted to check that my RAM is actually working at 2133 MHz.
Here is the screenshots of Memory and SPD tabs in ROG CPU-Z (latest version from CPUID website) when I had AI Overclock Tuner set to AUTO (so Target DRAM Speed in BIOS was saying 1333 MHz):

Here is the screenshots of Memory and SPD tabs in ROG CPU-Z when I had AI Overclock Tuner set to XMP (choosing Profile #1):

My computer is booting fine with no issues. When I check the BIOS after making the change to the AI Overclock Tuner the Target DRAM Speed is saying 2133 MHz.
Note: I have not changed any other setting in the BIOS.
MOTHERBOARD: ASUS Maximus VI Formula (BIOS 0804)
CPU: Intel i5-4670k
HDD 1: Samsung SSD 250G 840BW EVO
HDD 2: Western Digital WD10EZEX 1TB Caviar Blue 7200rpm
RAM: 16gb (2x8) G. Skill RipJawsX DDR3-2133
PSU: Seasonic X-Series 750W 80 Plus Gold
GPU: Gigabyte GV-N770OC-4GD
CASE: Fractal Design Define R4
OPTICAL DRIVE: Pioneer BDR-209DBK
MONITOR: Samsung S24C300HL; BenQ E2200HD
OS: Windows 10 Professional
Other: MS Wired 600; Logitech MX 310; Sennheiser PC 151 & Logitech Z150