Gigabyte Brix + 4K output over DisplayPort -> HDMI (AMD A8-5557M + R9 m275x)

[bunta714]

I recently purchased a Brix Gaming (GB-BXA8G-8890) with an AMD A8-5557M APU + a dedicated R9 M275X GPU.

The specifications show that 4K resolution (@30Hz) is possible when using the mini displayport output. However, I cannot get this to work with my Samsung 4K TV (UN65HU8550) with a mini displayport -> HDMI cable or passive adapter. Neither Windows 8.1 nor the AMD software show the 3840x2160 resolution as a choice anywhere.

*Note* I also have an Intel HTPC with an i3 CPU and HD 4400 graphics that is able to output the 4K@30Hz resolution over HDMI and (normal) displayport without any problems on the same TV.

I thought that maybe it had to do with the AMD Switchable Graphics function that seems to only enable the APU for the majority of things in Windows, but even when switching to a game or program that is configured to use the dedicated GPU (with AMD's software), I cannot get any resolution above 1920x1080. I have not found a way to disable Switchable Graphics and there are no settings in the BIOS to disable the iGPU and only use the dedicated GPU.

Does anyone know if getting an active mini-DP -> HDMI cable would help with this problem?

Is there any way to disable AMD Switchable Graphics and set the dedicated GPU to be used exclusively for everything?

 

[ihog]

Check here: http://nvidia.custhelp.com/app/answers/detail/a_id/2967/kw/displayport

I know it's not directly relevant to what you're doing, but it made me think that maybe your adapter is incapable of outputting 4K. Putting aside, for now, the possibility that an active adapter is necessary to achieve what you want, if the HDMI part of your adapter is not revision 1.4 or higher, it won't be able to handle 4K at any hertz. Could you post a link to the adapter?

 

[Brunostako]

Have you tried the HDMI output? (even if it says Full HD is the max res.)

 

[bunta714]

Check here: http://nvidia.custhelp.com/app/answers/detail/a_id/2967/kw/displayport

I know it's not directly relevant to what you're doing, but it made me think that maybe your adapter is incapable of outputting 4K. Putting aside, for now, the possibility that an active adapter is necessary to achieve what you want, if the HDMI part of your adapter is not revision 1.4 or higher, it won't be able to handle 4K at any hertz. Could you post a link to the adapter?

Thanks for the reply and the link.

This is the cable I tried:
Belkin Mini-DP -> HDMI

And this is the adapter:
Belkin Mini-DP -> HDMI Adapter

They are both passive, and there are reviews/comments that say there are people who have gotten them to work with 4K resolutions on several different systems. There seem to also be some who were not able to get it to work, however =/

 

[bunta714]

Have you tried the HDMI output? (even if it says Full HD is the max res.)

Yes, I have tried with the HDMI output. The same problem comes up.

What is also bit strange, I just noticed, is when I open AMD CCC and look at the "My Flat Panel Displays" information, the "Maximum reported resolution" for the TV is shown as 1920x1080 @ 75Hz. That doesn't seem right.

 

[ihog]

Sometimes TVs can supposedly achieve that, but it's not recommended. Under refresh rates, if one is italicized, I'm pretty sure it means the display isn't natively able to use it.

http://www.amazon.com/Accell-B086B-007B-UltraAV-DisplayPort-Adapter/dp/B00F90H7IO

So, yeah, that should theoretically work, but, ya know, same thing happened with your previous one.

 

[bunta714]

Sometimes TVs can supposedly achieve that, but it's not recommended. Under refresh rates, if one is italicized, I'm pretty sure it means the display isn't natively able to use it.

http://www.amazon.com/Accell-B086B-007B-UltraAV-DisplayPort-Adapter/dp/B00F90H7IO

So, yeah, that should theoretically work, but, ya know, same thing happened with your previous one.

I went ahead and ordered an active adapter similar to the one you linked. It came yesterday and after hooking it all up, everything is working great! The only annoying thing is that with the adapter, I have to have a second connection (via HDMI to my receiver) to output audio 🙁

Oh well, at least I'm getting 4K now. Thanks everyone.

 

[ihog]

No problem. Best regards.