I recently overclocked my 3770k up a few more notches to 4.5ghz. I don't think I have seen this before, but I guess I never really checked. The cpu goes back to 3.5ghz on occasion, but then back to 4.5ghz. I though maybe it was throttling, but the highest temps I have read is 79C and since I got home, its been 69C. Everything seems to be working okay as it returned 42k ppd yesterday. Any ideas?
I bet it is an Asus motherboard. You are only changing the max turbo freq. to 4.5GHz. It is behaving exactly as it should.