I also have the Airboost Vega56 and had game crashes and poor performance when I first got it. Not to worry..
I don't know what your level of expertise is with PC's but if you are comfortable with it you should read about UnderVolting your card. **Do this at your own risk, you can fry the card if you just go ham changing things incorrectly or randomly** Mine runs FANTASTIC now after about 2 days of off and on testing/benchmarking/stress testing. It runs cooler, faster and demands less wattage than the out-of-box settings. The Vega series (as mentioned above) are powerful power hungry cards. That means heat. The Airboost does a great job of keeping things cool, but not on stock settings....it needs tuning.... by you. You can go with the traditional "Balanced" wattman settings from AMD but I noticed things start to get too warm for my liking and the card begins to throttle its performance sometimes until it outright crashes. Not cool. 
If you message me, I can tell you some of my conservative settings I've found to run very cool, and very stable with great performance.
If you want the full clock speed (or real close to it) the whole time you game, you're going to need to tune your fan curves, lower your voltages a little, and leave all else alone. This will feed less voltage to the card (Vega likes this), which means less heat being produced equating to higher more stable clock speeds. Its a tuners card, and I became addicted to tuning it then I reap the benefits whenever I game 
Good luck I hope this helps.
