Kaveri displayport 3440x1440

[fallenbit]

Hi,

sorry if this is a bit off topic to radeon drivers.

Does anybody know whether Kaveri can support one of the newish 3440x1440 pixel monitors via displayport at 60 Hz in a single drive?
I have a 7850 here and would like to give it a try as the 2 different 24" monitor setup I used many years with NVidia blob seems broken with radeonSI.
I cannot make ZaphodHeads work. So I had to switch to a 2 screen layout which is odd if you move to another virtual desktop on one screen and the other screen changes it's contents as well. And launching programs or pop-ups of many programs are not display aware and are showing up on another screen on which their parent application is shown. (Not good, if this other screen is dual use and currently showing a TV program from a vdr installation. :-( )

According to the data sheet (found on ct, german computer magazin, but from the amd web site) it cannot:

2560x1600 at 60Hz or 2x 1920x2160 (but this would then be MST (multi stream support?)).
I would like to avoid MST (it's new, is it working reliable already?).

But may be somebody has running a 3440x1440 monitor at 60Hz with Kaveri and with good success? How?

I'm on Arch Linux, so pretty up-to-date, but not at git level.

Regards,
fallenbit

[bridgman]

My understanding is that Kaveri can support 4K/60Hz via DisplayPort and 4K/30Hz via HDMI. Haven't tried it myself so don't take that as fact unless/until I can dig up some confirmation. Might be possible to use 2 HDMI links for 60 Hz on certain monitors but I'm even less sure about that.

[duby229]

Yeah, zaphod is broken again. It was broken, and then it got fixed. I was so ecstatic. But it broke again.... :c

[Kano]

@fallenbit

Please read:

https://en.wikipedia.org/wiki/DisplayPort

You need MST or it won't work as AMD has only DP 1.2. Use a recent kernel.

@bridgman

HDMI is by defintion single link, it is not DVI. HDMI 2.0 allows 4k/60 Hz - the question is which AMD chip supports it... Fiji: no, Carrizo: ?

[chithanh]

You need MST or it won't work as AMD has only DP 1.2.

Um, what? DP 1.2 is totally fine for that resolution, MST or not.

[Kano]

Sure, but requries a kernel with radeon MST support like 4.1.

[chithanh]

I don't know of any 3440x1440 monitor that is MST. To my knowledge all are SST.

MST was only widespread in the early days of 4K (3840x2160) monitors.

[bridgman]

HDMI is by defintion single link, it is not DVI. HDMI 2.0 allows 4k/60 Hz - the question is which AMD chip supports it... Fiji: no, Carrizo: ?

Yeah, I probably should have said dual HDMI cables. There are a number of tiled 4K displays out there which present as dual 1920x2160 displays, so you can drive them with two HDMI cables. Example :

http://www.tomshardware.com/reviews/pq321q-4k-gaming,3620.html

I'm getting conflicting responses about HDMI 2.0 support, will try to get a definitive answer next week.

[fallenbit]

Thanks everybody for your input.

So I'm stuck:

a) Kaveri does not support this resolution via DP.

b) There are no monitors in this resolution with MST (a LG has 2 HDMI inputs for Dual Link, but I could not download the manual to check for MST) AND my motherboard has only ONE HDMI port.

I could always put in a separate graphics card, but that's not why I bought an APU.
I'll wait for now and monitor the development in this area.

[bridgman]

When you say "this resolution" are you talking about 3440x1440 ? If so it seems odd that Kaveri wouldn't support that via DP when it supports 4K via DP (I'm pretty sure Kaveri supports DP 1.2).

Seems like some monitors might have settings for DP 1.1 vs 1.2, don't have details yet.