Upgrading Processor

for about 2 years ago, my potatoe laptop can run almost any game that released before 2010 without almost no fps problem on the lowest settings, But now, i dont know why but my laptop feel much slower than before i always got random fps drop in any old games i play So im starting to think to...

i got a new computer and it over heats and overclocks even without doing anthing, usually around 80 degrees and its 3.4ghz but overclocks its self to 3.9....this is even while idling heeeelpp....also really bad frame while playing games my specs Operating System Windows 8.1 64-bit CPU AMD...