Overclocking settings for Nvidia 1060 6gb

Hello Grin people (Griners? Grinders?),

I’ve set up Ubuntu server 18.04 for my mining rigs, with 6 GTX1060 6Gb inside.
Stock, I got around 1,9GPS/card. Now I’d like to make it better, if possible.

How can I can increase these numbers by OCing the cards ? Should I increase mem frequency and lower core ? Or increase both ?
The idea is to get the max GPS/Watt as I’m not running free electricity.

Thanks for your help!

I tried to set up Ubuntu desktop with 2 GTX1060 but I could not assign the drivers. Do u have a manual?