Is there a big difference between the i5 2500k and the core i7 2600k? I know the core i7 supports hyper threading, would those extra threads give me better performance in gaming compared to if I were to buy an i5 2500k? (I currently have an i5 2400)
imo stick with the 2400 unless you're using your pc for multithreaded works. for gaming, 2500k is very good. but your current 2400 is no slouch either.
core i5 2400 vs 2600k(stock) http://www.anandtech.com/bench/Product/287?vs=363
you'll notice that the 2400 can keep up well with the 2600k(stock) in gaming, only losing in highly threaded tasks.
no, HT enabled reduces 1 - 3 fps, i speak from experience because i have the 2600k. Even it adds arround 2 seconds @ windows 7 startup (the "briks" from the windows 7 loading screen dont merge together @ startup when i have HT disabled, but when i do enable it the briks merge , PS i have an SSD )