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
It is not going to be related to drivers as they are only loaded after Windows has booted.
I would contact your Motherboard manufactuer, they should be able to help you troubleshoot the issue better than anyone here.
I can offer some suggestions.