M3E will support 2000MHZ. but the problem lies within your CPU Integrated memory controller and whether or not your CPU can handle the frequency. even if you have identical cpu models, the IMC may either be stronger or weaker to support 2000MHZ. now it can entirely be done, but it really depends on the IMC quality and what or how you use it.
hopefully this analogy helps: if you overclock a gpu to 1GHZ, it may be stable running a game, but may not be stable running furmark. same with this memory question, yes 4 dimms should work at 2000mhz, but stability will be based on whats being run.