No idea why the cpu never went more then 4.6 , i did many different test , last one being a re-encode of a blue ray , cpu maxed at 100% for 15 minutes never went over 4.6?.. i have an offset on adaptive voltage of 1.3v ... wonder if it's that avx instruction core ratio negative offset causing this.
If encoding a blu ray utilizes avx, it could be that. Of your offset for avx equals 4.6 that would explain it. To rule it out, try using aida64 or something similar without using avx function and see if it maxes at set OC. Just trying to cover all bases. You may have done this already.