When I turn on my computer, my monitor will have no signal with my card's fan going at about 30% and RADEON lit up, but no GPU tach. This can last up to a minute. Then the fan goes down to a regular idle and the computer boots up like normal. When I get to Windows, everything will lag, loading pictures will get slight artifacting, and games and videos will have distorted/corrupted audio and will struggle in the single-digit FPS until they crash. The only solution is to hit my PC's restart button during the long boot until it turns on regularly. I only saw this when I switched to my Vega 56. I've tried uninstalling and reinstalling drivers, switching around PSU cables, switching PCI slots, and toggling the BIOS switch. If I spam the restart button, the card runs fine. Just for fun, I started with my C: drive unplugged and the computer booted to its BIOS screen almost instantly, no weird lack of signal or anything. Has anyone else had this?
i7-4790K @ 4.4 GHz
2x8 GB DDR3 2400 MHz RAM
Gigabyte Z97X-Gaming 3, F6 BIOS
EVGA 550 GS
Asus VN248H-P, 1080p 60 Hz HDMI
Sapphire Radeon RX Vega 56
Tried with 17.11.1 and 17.11.2