[erauman]

#1 four sticks of ram require a 2T setting
#2 you have value ram, which many times doesn't ran faster than 215mhz, and 4 sticks of ram always run slower than 2 sticks, so you are most likely close to maxing your ram. You'll get a better overclock if you take two sticks out. Otherwise, you'll have to run a divider
#3 you should bump your vcore up one notch

 

[erauman]

You need to run memtest and find out what the max speed your ram can run at stabily, from there you can determine how large of a divider you have to run to get the overclock you want.