Confused About DRAM Frequency

CPU: FX-6300 with a DEEPCOOL Gamer Storm CAPTAIN 120 Liquid Cooler
I have used the bios CPU OC mode to 25% 4.3MHz. havent changed anything manually didn't realize it would affect memory. What should i set the memory to?
 


That's why those odd memory speeds are offered. You used the built-in OC'ing function. It changed the base clock freq which changes the memory speed too.

Set everything back to default, and the memory speed offerings in BIOS will be normal again. Then do your OC'ing in BIOS manually by disabling turbo mode, increasing the CPU clock multiplier an increment at a time, saving, and booting back to Win. Run a stress test, watch temps and if all is good, repeat the multi increase.
When you get a unstable stress test result, increase the core voltage as little as you are allowed in BIOS and try again. When stable, you can try a higher multi increase. But stay below 1.5V vcore for now.

A quick stress test I like to use is Intel Burn Test at the default settings. http://www.majorgeeks.com/files/details/intelburntest.html
It's quick, and if it passes that, it is generally stable enough for gaming.