To overclock the Strix 2060, we used ASUS GPU Tweak II. We were able to add an extra 35MHz to the GPU core (on top of the extra 30MHz provided by the OC Mode preset), and 750MHz to the GDDR6 memory.
3DMark and games testing
Given this card is already running very fast out of the box, it is not a huge surprise that manual overclocking headroom is limited. That means we didn't see much performance benefit from the extra frequency, with an extra 2.5FPS in Shadow of the Tomb Raider being about as good as it got.