4.4GHz is only 5% faster than 4.2GHz. The difference in performance when it comes to games is nearly non-existent. The only game I know which will benefit from that increase is Sim City. Based on a review using core i5 4670k CPU, performance seems to scale with the CPU speed perfectly. If you decrease the CPU clockspeed by 10% you will see a decrease in performance by 10%. Increasing the speed by 10% means a 10% increase in performance. However, Sim City is an exception not the rule. At best games performance would only increase by half the CPU performance increase; 2.5% at best.
Above a certain clockspeed, games generally do not gain any benefits from a more powerful CPU. For example, Bioshock Infinite can run perfectly fine on a Core i5-4670k running at a mere 2.5GHz, to get 1 extra FPS you would need bump up to 3.5GHz. Go get another 1 FPS you need to bump up the CPU to 4.5GHz.