Dont think you can go higher than 4.5 without damaging IHS. CPU voltage will need to be raised (possibly NB voltage as well) and then before attempting any gaming you should run a rather long Prime95 test (assuming the system boots) while monitoring temps at the same time (they should never go over 75C on this cpu at full load). I would overclock in 100mhz increments, increase frequency by 100mhz, tweak voltages etc. until its stable, temps good, then push it more. ..and if the cpu fails (it sometimes happens), then you can only blame yourself for taking the risk.
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