what is strange, i have always problem with 3GHz at NB (AIR)...WTF? My 955 and now too 965 C3. The stangest is, with x4 955 at 2800+ i needed +0.3V. With C3 only +0.225V. But 3Ghz is impossible. With a luck sometimes im booting at 3000MHz at NB, but superpi crashed or windows frozed.