RadeonHD DisplayPort

My new 34" ultra wide QHD display arrived today (Asus VG34VQL1B).

First of all, 3440x1440 brings a complete new experience to AmigaOS IMHO. This resolution and size make it possible to using Codebench, the SDK browser and Odyssey side by side in a convenient way. So the lack of multi monitor support is fully compensated if you ask me.

But now the question. I have a X5000 with MSI Radeon R9 270x OC (2GB) and V3.6 of the RadeonHD driver.
I do get 3440x1440@60Hz using HDMI. Display port on the other hand shows uboot and the startup animation, but goes to black once workbench is opened. Is this a known limitation of the RadeonHD V3.6 driver? Do I have the wrong Radeon brand? Or are there any tooltypes or settings to enable display port support?

Well done with the new monitor. I was thinking about one myself, now that I work from home mostly, but other stuff are in higher priority.

As much as I know, the Radeon driver doesn't support yet the display port, and I believe it is low on Hans priorities right now, but I might be wrong as well.

@walkero


Ok thanks. Too bad because the displayport of my radeon is supposed to provide about twice the amount of bandwidth compared to the hdmi port. So it would have been nice to have a 100Hz refresh rate instead of 60Hz.

This also means that UHD (4K) is only supported up to 30Hz. I tried this with my TV and I cannot recommend this to anyone. You can see refresh issues when you move windows around. although there is no processing power issue, the system still feels sluggish.

@geennaam

Multi monitor is possible with most Amiga's, even the classic supported more then 1 graphics card.
The 'problem' is that 1 Amiga screen can't be divided on more then 1 monitor.

In fact I had a X1000 with 2 Radeon 7750's running a 4K Workbench screen and Pppaint on the other monitor.


But if you can't use more then 1 gfx-card there is always the Matrox solution I used: https://www.youtube.com/watch?v=buCtNuP--bI
But in this case limited to 3840x1024 pixels on 3 monitors and not so thin bezels...

Try contacting Hans. If he can find quirks for your particular card documented in the linux drivers he might be able to add better support for it in his driver.

@geennaam

How about a display port to hdmi cable.

@Cap

That disables the highrefresh that he wants, and he does achieve with Display Port.

@benny

Yes, that is the main reason. But it is more just I (my monitor) can than that I really need it.

Seems that Hans doesn't read these forums anymore. So I'll try to contact him.

@geennaam

Did you test your setup using a dual link DVI cable 2 hdmi/displayport ?

Dual link dvi can reach 9.9Gbps vs 4.59 single link.

3440x1440@30Hz = 4,46 Gbps
3440x1440@50Hz = 7,43 Gbps
3440x1440@60Hz = 8,92 Gbps

@benny

I've got confirmation from Hans that DisplayPort is not supported.

About DVI. You already calculated that at 3440x1440@60Hz the dual link dvi is maxed out.

These are the specs of my MSI R9 270X:

DVI CONNECTORS
DL-DVI-Ix1, DL-DVI-Dx1
Max Resolution: 2560 x 1600 @60 Hz

HDMI CONNECTORS
1 (version 1.4a)
Max Resolution: 3840x2160 @30 Hz
4096x2160 @24 Hz

DISPLAYPORT
1 (version 1.2)
Max Resolution: 4096x2160 @ 50 Hz

As you can see, the product of resolution and update rate for DVI is equal to HDMI.

The displayport is clearly superior because the product is of resolution and update rate is 66.7% higher. This would have enabled me to run workbench up to 3440x1440@100Hz (Depending on minumum blanking times) . It would have been a nice to have. But 3440x1440@60Hz is sufficient as well.

When the RadeonRX cards get warp3d support, I'll switch to such a card and the limitation should be gone because of hdmi 2.0b.

@geennaam

Quote:
Has Hans mentioned any hope that DisplayPort could be supported in a foreseeable future?

@trixie

It is low on the priorities list because almost every monitor has dvi or hdmi anyways.

So don't expect it anytime soon.

But if the powerstate ( as i understand it) issues with the rx driver have been solved and a warp3d driver had been made then I see no reason at all to support the displayport. So I understand why it is low on the priorities list.