Low GPU usage downclocking VR games RX Vega 64

I have tested both Project cars and Dirt Rally(relive) on my HTC Vive using the 17.8.1 driver .  Both exhibit the same problem GPU usage is as low as 60% and memclock downclocking as low as 500mhz along with core clock dipping below 1000mhz in Turbo mode.  Fans are on full and if I fire up a non-VR game like Crysis 3 or Witcher 3 I have 99% gpu usage and memclock pegged @945mhz along with higher core clock. 

 

Does anyone else with Vega 64 have similar issues with VR games as performance at this time in these 2 games is considerably worse than my Fury Nitro.