Overwatch RX 480 4GB AMD Athlon X4 880K [GamePlay]

So my RX 460 is broken right now, and the graphic card is totally dead (not showing any display on monitor) just a blank display and the fan didn't spin and i have to return my graphic card to the local shop to change my rx 460 to new, but apparently they don't have any stock of RX 460 so i have to wait till next month. So i decided to buy Sapphire RX 480 4GB Nitro+ to replace my RX 460. Btw Powercolor RX 460 is sucks... so my first test for this rig is overwatch.. It's bottleneck with this cpu @4.2Ghz. I always fail everytime I OC it to 4.5 Ghz. If u guys can give me some advice on how to overclocking this cpu, it would be helpful for me. Thanks and Enjoy :D PC Spesification : AMD Athlon X4 880K @4.2Ghz (Stock Cooler) ASRock A88M-G/3.1 FM2+ Sapphire RX 480 4GB Nitro+ OC V-Gen 2x4 8GB DDR3 SSD Sandisk Plus 120GB HDD Toshiba 1TB PSU GameMax GP-550 550Watt 80+ Bronze Current Radeon Software : 17.3.1 OS : Windows 10 Monitoring Software : MSI Afterburner Don't Forget to Subscribe and Like my vids