First I dont exactly need a solution, just want to try to understand what the problem is and how it is caused.
The pc is a new one and was buyed prebuild.
CPU: AMD Ryzen 7 1700x
Mainboard: GIGABYTE GA-A320M-S2H
GPU: Sapphire Pulse Radeon RX 550 4GB
RAM: 16 GB DDR4 3200MHZ
PSU: 700 W 80 PLUS
SSD/HDD: 512GB SSD and 2 TB HDD
On the last parts i dont have any more information, forgot to wrote them down, are not any more specific in the offer and computer is at my fathers home.
Tested the pc with Display Port connected to my 1080p monitor, but after just some minutes of use (Browsing and WIndows Settings) artifacts appear and display froze. After a short time display went black and back on and it worked again for some minutes and then again but this time display just turned black and we had to force a restart(PC was still running). Tried it several times, restarts, different display different connection(DisplayPort and HDMI) and looked for loose connections, transport damage and reseated the gpu but the artifacts always showed up after 1-5 minutes:
Tried it with a different old gpu in the system and we could do everything.
So obviously a GPU fault and probably a VRAM fault on the RX 550.
But now the curios thing:
Connected the RX 550 with HDMI and DisplayPort to the same monitor, both outputs worked and somehow everything worked.
Test it with serveral restarts, gpu and cpu "burntests"(Furmark) and could watch VIdeos/Movies for over an hour and the artifacts never showed up.
As soon as we disconnected HDMI or DisplayPort (didnt matter which one) the artifacts showed up 1-2 minutes after that.
Tried it with a "real" second display. DisplayPort on my Monitor and HDMI on my TV. Everything worked fine again for over half an hour even if one of the displays is on a different "input" Mode(TV Mode or standby and so on).
But as soon as we turned off one of the displays(no standby, but completely off(no lights on or anything)) the artifacts showed up again after 1-3 minutes.
Seems like the GPU has a VRAM problem with only one active connected Display but with 2 connected displays it works completely fine?
But why, is this a normal fault. Cause i absolutely cant explain this issues and why it works with 2 displays.
If someone knows more about that i would be happy about some explanation.
P.S. Couldnt test newer drivers cause of some internet problems, but can this be just a driver issue? (Tested with some unknown updated Drivers, dont know when they were updated last and with the factory settings/drivers)