ReasonsToBeDutch

Good day, I'm about to buy a used motherboard and processor. My current rig uses an Intel I5 2500K and I have an Z68 based motherboard. The motherboard and processor I'm about to buy are an Intel I7 2600K and an Asrock p67 extreme 4. The reasons why I'm considering this option is the need for more cores, even if the are hyperthreated. Therefor this is my question: What difference will I encounter? Thanks in advance!