I just wanted to let you know, that I didn't get my ASUS RX580 (8 GB) to work with Vegas Pro 12-14 - latest ATI drivers (17.5.1), latest patches (Windows 7 x64, Vegas 12/14). So if anyone is considering the latest AMD Polaris cards, you'd better stay away from them until this is sorted out. Even when GPU acceleration is switched off, Vegas will only run once after a Ctrl-Shift-start and crash during every other following startup.
It reports an unmanaged exeption in the ati driver.
Or has anyone managed to get a RX5x card to work properly?
EDIT/LATEST INSIGHT:
The startup crash just occurs, when the Vegas Pro 12/14/14 main applicaton window is starting up on an Intel internal VGA display with one or more ATI extended desktop displays enabled - regardless if GPU acceleration in Vegas prefs is enabled or not.
Quick Fix: As soon as the main application window starts up/has been saved on an ATI display while quitting VP, the problem is gone and VP doesn't crash at startup.