The power output limits of the hub are internal. If your input power can push more than about 12V/12A, the hub itself will be the limiter in how much juice you can deliver to sticks.
If you're going over about 8 amps, you need to use the 6-pin. The barrel is rated for 8A max.
Ive plugged in a 6pin S9 psu to the hub but seems like I need to bump up the MHz to receive the Gh I was off using a barrel?