Sapphire R 290x CF and Samsung 4k U28D590D issues

[Johnmcl7]

I've a friend with pair of Sapphire R9 290x 4GB cards and a new Samsung U28D590D (28in 4K monitor) which isn't working properly, with the supplied displayport cable (connected displayport to displayport directly) the image is low quality showing constant artifacting and snow effects while an expensive DP1.2 Lindy cable he bought doesn't show anything - the monitor and PC both show as being connected but there's nothing on screen. Displayport 1.1 cables work fine but limited to 2560x1440.

Thinking there was something wrong with the cables or monitor I tried it with my PC's, I couldn't get it working properly with my desktop (crossfire 6950's and using mini displayport) as 2560x1440 was the maximum resolution I could choose or 1920x1200 over HDMI (I normally run the system at 1440p over DVI). However a topic here claims pre-GCN AMD parts were not good for 4K or possibly the mini-DP to DP adapter I'm using is no good (no full size display ports on the card). There's a topic on the Sapphire forum where a few people seem to have the same issue and recommend trying different cables.

However the monitor and both the cables work perfectly in a GTX 760 system I have (MSI version with the stock cooler), it has a standard display port connector and when connected this way the system ran at 3860x2140 @ 60Hz without issue while on hdmi it ran at the full resolution but at 30Hz.

I'm a bit puzzled what to recommend when it's working fine with the GTX 760, I've searched the forum for advice but the one person I can find with this monitor and R9 290x's says they are working fine. Any thoughts on something I've missed?

Thanks,
John

 

[AkumaX]

Crazy -- the fact that it's working perfectly with the GTX 760 but not with the 290X

I had it working fine w/ a GTX 750Ti and 7870 GHz (both have native DP). It's gotta be drivers or something...

Note that the U28D590D is the 1st 3840x2160 @ 60Hz monitor that does it over SST (most other monitors do it via MST, or 1920x2160 x 2). IDK>>>>....

 

[Johnmcl7]

The friend who owns the monitor also wondered if it was something to do with SST/MST, he's spoken to Lindy and they've said there's known compatibility issues with the monitor (I've asked him to see if they can clarify if it's a graphics card issue as well). They've advised returning the cable and getting a revised version they're about to release.

John

 

[Skurge]

I don't have an issues. I'm using a Generic HP display port cable. no the one that came in the box. I don't even know if the cable is DP1.2

EDIT: I just tested with the one in the box and no issues.

 

[Johnmcl7]

I don't have an issues. I'm using a Generic HP display port cable. no the one that came in the box. I don't even know if the cable is DP1.2

EDIT: I just tested with the one in the box and no issues.

I take it that's with the Gigabyte 290's in your signature?

John

 

[KaRLiToS]

Maybe your drivers are not installed properly.

I have QuadFire Sapphire 290x with the U28D590D and I don't have any issues setting the resolution at 3840x2160 @60hz. I am also using the included DisplayPort cable supplied with the monitor.

What drivers are you using?

 

[Johnmcl7]

The person has tried a variety of drivers and they've all been the same, there's no other issues with the cards (no instability or other similar issues as you'd expect from a bad driver install) so I don't think it's the drivers. This is the forum thread on the Sapphire forums, they're reckoning it's a cable issue although that doesn't seem to match up with what people here have found:

https://www.sapphireforum.com/showthread.php?33238-Sapphire-R9-290x-and-Samsung-U28D590D-4k-Issues

John