If for gaming...G2020 seems doesn't as powerful as Q6600. After all, Q6600 is a quad-core processor while G2020 is a dual-core processor. G2020 may be as powerful as E8400 but still be outperformed by Q9650. Also G2020 isn't good for overclocking, meaning u couldn't squeeze any performance while Q6600 still has a chance to be OC'ed. Only i5 could be a good replacement for it. Downgrade your quad-core CPU to a dual-core (and only two threads) CPU isn't a good idea. Save some money to buy a good cooler and OC your Q6600.