[Possibly Off-Topic] Issue with Video Card on GA-H55N-USB3

[mcnuggets]

Hi guys,

Hope I'm all good to ask this question here. I'm not even sure if it's really relevant to what you guys are doing but I thought I'd try anyway.

I have an H55N-USB3 Mini-ITX board that I purchased used. I'm using it with 8GB of DDR3 1600 Memory and an i7 860 Processor.

Now whenever I try to get the system to boot with my main GPU, an R9 380 4GB (Sapphire) card, it generally just gives no video output. Rarely it will boot with a corrupt BIOS splash screen. You can see an image HERE. After the corrupt BIOS Splash Screen it will boot to Windows 10 fine, and from then on it's rock solid. Even under load. But it can sometimes be very difficult to get it to this point.

If I insert an old non-powered ATI 5670 GPU it boots with 100% certainty, including a clear normal BIOS Splash Screen. What I also thought was a little weird is that after booting with the 5670, if I put the R9 back in it will boot with almost 100% certainty. It will still have the corrupt Splash Screen but it will boot. After a power down it will return to only booting with video output maybe 1% of the time. Sometimes as soon as I enter the BIOS menu it will also freeze and after a minute or two it can unfreeze which I thought was even more odd.

So sorry for the lecture. I feel like I had to go into detail, I'm pretty confused by it all. I was wondering if modern GPU's such as my R9 could perhaps simply just not be supported, or require a feature that the old Legacy BIOS offered from my board doesn't have? Do you think it could be a BIOS bug? And does this sort of thing happen often?

Apart from this, I've tried pretty much everything you could think of. Several brands of RAM in various slot configurations at different clocks, I've tried two different power supplies, setting the R9 to UEFI and Legacy mode, changing CMOS settings, etc. Nothing I try makes it appear any more stable. I've also tried BIOS revisions F1, F5 and I'm currently using F6A (Beta).

Anyway, thanks for reading. Again, I hope I'm not making a nuisance post. I asked about this over on another forum and nobody really had any idea what was going on so I thought I'd try my chances here. Thanks.