Question AMD Phenom II X6 Overclock

[b0b1]

Hello! I recently upgraded my GPU to an Radeon RX 560 4 GB, and it can't run to it's maximum power because of my CPU, it bottlnecks, and the only way to solve this problem is by overclocking the CPU because I don't afford a new one atm.
I've never overclocked a CPU and I'm going to need a lot of help, step by step.

First of all I want to show you all my other PC components:
CPU: AMD Phenom II x6
MOBO: ASRock 970 Pro3 R2.0 ( https://www.asrock.com/mb/AMD/970 Pro3 R2.0/ )
Cooler: Zalman CNPS9900max ( not stock: https://www.zalman.com/contents/products/view.html?no=367 )
RAM: 8GB DDR3 1333 frequency
Power Supply: Corsair TX650 80 PLUS Bronze 650 watt: ( https://www.corsair.com/us/en/Categ...High-Performance-Power-Supply/p/CP-9020038-NA)
HDD: An old 500 gb but i don't think this one is relevant

First of all I want to know if my current rig is capable of overclocking this GPU and to what extent, 3,5ghz, 3,7ghz..etc. I would love to find someone who can help me step by step.

Also my CPU Temp on idle is 21C

 

[vcc98554vn]

that cpu really hot and need a good cooling solution to overclock , and it have old artitechture so it cant run new game properly
see if your mobo support am3+ , go for the fx 8350
or just sell the main cpu bundle and spend extra money on b75 and i5 3th gen for better performance

 

[b0b1]

that cpu really hot and need a good cooling solution to overclock , and it have old artitechture so it cant run new game properly
see if your mobo support am3+ , go for the fx 8350
or just sell the main cpu bundle and spend extra money on b75 and i5 3th gen for better performance

but i've seen it's a really good over-clocker, idk, also i don't have a stock cooler so that should be a bonus