Dell U3415W UltraWide screen only able to run with PAL 50Hz

[datadl]

Hello!

First of all, I would like to thank you for this great forum as everybody seem to be nice and give A LOT of info.
I hope I can also contribute since I am a newbee there.........

Well I had some struggles setup my system, but by the end of the day I got it working well.
First of all I had the black screen issue because I use a Saphire HD7770 with AMD GPU.
I fixed it with modifying the AMDRadeonX4000.kext (by following this thread: http://www.tonymacx86.com/yosemite-...update-black-screen-cursor-2.html#post1018020 ).

Then I got only my Dell U3415W UltraWide screen working with the HDMI port @ PAL 50hz.
I wanted to be able to use my displayports (I have also an Apple LED 24" screen).
The LED works fine with displayport but the DELL doesn't.

I finally got the DELL work with Displayport but still only @ PAL 50hz by changing the Framebuffer to DashimakiS (with the hex key) with Clover Configurator.
This is the only fbname that works with my graphic card (which is now recognized when I go to "About this mac").

I searched everywhere on the internet and couldn't find a solution to get my screen to work with NTSC 60hz.

If anyone could give me a hand there that would be great!!

Thank you very much.
Vincent

 

[Fl0r!an]

Did you try using the DisplayPort without injecting any framebuffer? Which ports does you 7770 have? 2xmDP or 1x full-size DP?
For a 2xmDP card Dashimaki should usually fit...

 

[datadl]

Hello Fl0r!an !
Thanks for replying to me this fast!

Without injecting the framebuffer, the DELL won't work with displayport, only HDMI.
But what is even more strange is that the monitor is recognised (I can see it under System Preferences, but it stays in PowerSave mode) (when I have no framebuffer OR that I try to use it with NTSC 60hz with the framebuffer injected).

I have 2xmDP, 1hdmi, 1DVI : http://www.amazon.com/gp/product/B00782U10C/


I hope you understand everything I said

Cheers

 

[Fl0r!an]

Okay... That's strange!

Can you verify e.g. in Windows that the exact same setup is working? Maybe your DP cable doesn't support the full bandwidth you'd need for 3440x1440@60Hz? Will the dispaly come to live when changing (lowering) the resolution?

 

[datadl]

I have a MacBook Pro Retina Mid-2012 and I can get a 60Hz with the DELL screen.
Also I tested with lower resolutions and it doesn't work..

I also tried to change the smbios with other configuration (saw people with issues having their 4K screen to work fine with some names), but it didn't change anything!

50hz is not terrible, but 60 would be better

Cheers

 

[datadl]

[SUCCESS] Dell U3415W UltraWide screen only able to run with PAL 50Hz

Hello there!

I finally found out that disabling the displayport 1.2 in the OSD of my monitor would enable the screen at all time with all resolutions and 60HZ NTSC !!!!!!

Found that there: http://www.tonymacx86.com/graphics/159791-ultrawide-3440x1440-monitor-not-detected-yosemite.html

All the best,
Vincent