Here is the list of CPUs supported by your motherboard -- https://www.asus.com/us/Motherboards/A68HMPLUS/HelpDesk_CPU/
If you have a graphics card then an 860K is the best choice. If you don't have a graphics card, then BUYING a graphics card and then swapping to an 860K is the best choice.
Unfortunately you are kinda stuck buying a new motherboard (and new RAM unless you get an older system) if you want a better CPU. The 860K is a mere 400Mhz faster than your current chip
Unfortunately you are kinda stuck buying a new motherboard (and new RAM unless you get an older system) if you want a better CPU. The 860K is a mere 400Mhz faster than your current chip