When taking into account overclocking for the Vega cards, you must keep in mind that there is a power limit set (220W limit for the Balanced WattMan profile), but also a temperature limit. When either of these are reached, the frequency set in GPU Tweak II utility will be automatically lowered and will keep modifying on-the-fly depending on the benchmarks or games we do run. We did really like the Unigine Superposition benchmark in particular, because of its ability to show the live GPU/memory frequency but also the GPU temperature. With this utility, we have also seen the highest top clocks and with the default (Balanced) Wattman profile we have succeeded to obtain a 14441 score while running with the 1080P Medium preset.

Increasing the stock clock while using the default 1200mV for the core seemed to hit the power wall so the direction we have chosen to go was to decrease the core voltage to 1100mV (the minimum value allowed by GPU Tweak II). Besides the fact that the card has proven fully stable at the new voltage, we could also increase the GPU clock from 1630 to 1650MHz; for this particular setup, we have got a score of 14638:

The next experiment was to leave the stock clock, but also decrease the GPU voltage at 1100mV and at the same time set the fan speed to maximum; with this setting, we have seen the highest Boost jump (1553Mhz) and we have got a maximum score of 14942 in Unigine Superposition. The downside is clear -> leaving the card at maximum RPM is not the way to go because of the high noise levels:

The third experiment was to leave the stock frequency as-is, the stock voltage at 1100mV for the GPU, but at the same time increase the memory clock from 1900Mhz to 2100Mhz; with the increased memory clock, we did not experience instability in games or Unigine Superposition and the score has been raised to 14773: