Try using a RAM divider, losen up the timings a bit if you don't, and 2.8V should be enough for your RAM if it isn't something like Bh-5 or w/e it's called. Also try upping the Vcore slightly for the cpu, VERY SLIGHTLY!!!!
1: Use a RAM divider. (Or loosen up the timings, it would help if we knew what kind of ram your using, and 2.8V for the RAM should be enough, but 2.9 is the highest I would ever go with RAM unless it needs it.)
2: Up the Vcore slightly, like 0.25% at the most is what I would say.
3: Try upping by increments of 3, because stock being 200*9 = 1800Mhz, and 206*9 = 1854Mhz, might just wanna take it a little slower.