MSI RADEON R9 380 Gaming G2 BIOS TV314MH.201
Intel Core i5 4460
Crucial 2x8GB DDR3
Cooler Master VS V450S
Screens (tested with both separately):
Philips BDM4065UC (3840*2048)
BenQ G2400WD (1920*1200)
OS (issue happens on all):
Usually when I boot up my system it goes really slow. The windows bootloader screen takes a few seconds to appear on the screen (loading from top to bottom). I usually reboot at this point which somehow makes it a bit faster again, but if I start up windows it will be unbearably slow. Trying to draw a selection box on the desktop freezes the system for multiple seconds. Starting a 3d game will work, but it will have incredibly low fps and the system will feel generally unstable.
Rebooting the system a few times and only going into Windows when the bootloader screen loads instantly, gives me a workable system. But I still get weird ~5 second periods of low fps in games like Overwatch and Street Fighter 5. These games crash weirdly sometimes.
I know this isn't a Windows issue either, because I dual boot into Arch Linux. If I boot into Linux when the bootloader is fast, I rarely have problems. But if I just boot into Linux straight away I also get low fps in games and stuttering video.
I know this is a graphics card problem, because if I use the internal GPU from the i5 instead, I get a blazingly fast system every time. I also know this isn't a power supply problem, because starting something graphically intense doesn't cause extra problems. It's also not a problem with either OS or drivers, because even the bootloader screens en bios screens are slow on certain boots.
Is there any fix for this? Are there any more tests I should do to find out if this card is faulty? Thanks