Not being able to select discrete GPU as an option

[SoundT3ck]

I tried to build a low-cost ryzen platform for everyday tasks and some light gaming:

 

MSI A320M PRO-VD/S V2 mobo w/ bios update to accept newer gen ryzens

Ryzen 3200G

16GB @ 3200mhz (2x8gb)

sapphire RX470 mining (no display outputs)

Corsair cx520 PSU

 

I reused GPU from my older PC (i5 4590) in which iGPU worked as a display output for the discrete GPU without any real problems. After switching to this "new" PC, I quickly discovered that i can not opt for discrete GPU as a "high performance option" in graphics options in win10.

 

Upon initial gpu installation, my first thought was to be some bios setting preventing it from doing so. However, even after changing multiple settings (enabling/disabling re-bar, above 4G decoding, changing PCIe lane gen....) GPU is still being recognized in device manager, drivers are installed without any problems and GPU status is "working fine".

Magically, when I reenabled re-bar, I was able to select RX470 as a performance option... for one power cycle. After turning the PC off and on the next day, I was greeted with iGPU as both power saving and performance option once again.

 

As my last option to rule out mobo being the culprit for these issues I tried to use an OEM GT730 which I was able to select every single time, even after restarting my PC. I also tested RX470 in my old rig, which is now used by my gf and again, card works fine.

 

At this point, I have no idea why it does not work. Is it some problem with AMD iGPU-AMD GPU combo ? Or is it something else? If so, why did it magically work once ?

Any help is appreciated

[SpookyCitrus]

This is most likely going to be a problem with the new board/CPU, possibly the APU causing some sort of issue with the dGPU being able to output through the board when it's in use, or something else entirely. Those mining cards are not meant to be used like this and require tweaking software or specific hardware to work like that. Most likely you will only be able to use it in that way with an Intel based system. 

 

You can try disabling the iGPU in device manager/bios and that should in theory let it only use the dGPU for output but those mining cards are iffy. If you disable it you might not be able to get display at all anymore which would let you know that it's not going to work the way you want in that configuration.

 

If I were in this predicament, personally, there are so many inexpensive standard dedicated GPUs out there that are much better than that mining card, I wouldn't even mess with it. I'd cut my loses and buy a used RX 580(super inexpensive) or go for a used RTX 20 or 30 series. Hell, the new RX cards aren't super expensive either. 

[SoundT3ck]

Thanks for the answer

This build is not my main rig, just a little something out of stuff I had laying around. I definitely agree that it would be much easier to just slap a "fully working" GPU inside and call it a day. Since I do like tinkering with this niche usecase stuff, I just figured that APU should work just like that old I5 w/iGPU and decided to f*ck around to eventually find out And tbh, I would give up on this idea completely if not for the short time it actually worked just like it did in the intel build. That made me even more curious about it, so I decided to make a post in hopes that maybe someone equally as dumb as me had already encountered such problem before.

 

And about your idea of disabling IGPU - I had the same idea and tried it. I still had a display out and windows even offered RX470 as both power saving and performance option but in actual gameplay it looked like when you forget to install drivers and just bruteforce it with "basic display adapter", meaning low FPS and/or screentearing.

 

I will try some more stuff and can give you an update if you are perhaps interested