I don't know exactly what you mean by "performance issues" but I would be surprised if it is the CPU.
Just go back to default (with "XMP" for memory), SAVE, then see if things are okay.
Running at 4.5GHz OC would have little to no benefit to your real-word experience as that's probably only about a 3 to 7% boost at most (under load) which most programs can't even benefit from.
(default is Max Turbo of 4.4GHz so probably 4.2GHz or so under heavy load)
For better info give more detailed information:
a) CPU cooler
b) exactly what issues you have
c) what games/programs you use
d) graphics card (if gaming)