Well, I read a lot of posts claiming that they DO have improvement. Also, my system was stable @99x5.5, but it freezed after two-three minutes of 100% usage at 100x5.5! After two days of burn in it works great at 100x5.5. I am sure it is going for more Mhz (or less voltage). Its not great improvement, but it is a clue that burning in can improve overclocking performance...