For our manual overclocking tests, we used AMD's built in tuning tool. Our best results are as below.
We set the minimum frequency to 2400MHz, the maximum to 2900MHz and the memory slider up to 2700MHz.
This saw GPU frequency increase to 2754MHz – up by about 170MHz.
This overclock netted performance gains of 6-7%, which is OK but not outrageous.
Power draw did also rise considerably, up from 312W to 363W, a 17% increase.