Recently purchased a Sapphire Vega 56 Pulse for my 2010 Mac Pro running on Mohave 10.14.6. The card runs fine until i try running a benchmark such as unigine heaven. Half way through the benchmark the Mac shut down completely. I remember reading that for a Vega 56 card, the Pixlas power supply mod isn't necessary. Is this issue power supply related or something else possibly?