AMD FX processors support:
1600MHz with all four memory slots filled. (two DIMMS per channel)
1866MHz with two slots filled. (one DIMM per channel)
AMD FX CPU's don't support 2133MHz speed unless the system is overclocked. You could run 2133MHz memory at a slower memory clock. Normally you wouldn't run the memory hardware at a higher memory clock speed than the memory rated specification..