Lost ability to choose 3440x1440 resolution

meanwhile I "upgraded" my MacMini back to Yosemite - and you're right: despite of using "old" File, still only "low res" (2560) available...Eventually this is also a "graphic driver" restriction....It seems that all at least all HD4000 Mac's do not support higher resolutions....My MBP is a 13'' Retina (Late 13) so an Intel Iris Chipset. Thinking back: Eventually it would have worked (native res with 34UM95) also in "unmodified" Setup....

Investigating further.... - and in worst case reverting back (again) to Maverick this afternoon.

"It seems that all at least all HD4000 Mac's do not support higher resolutions."

I'm not sure about this one - my macbook air 2012 with intel HD4000 supports the 3440x1440 when I have mavericks installed, on upgrade, it only supports 2560x1080.

it looks like the framebuffer size in the driver is probably the correct assumption as to the cause of this - hopefully apple see this post and up the buffersize for us so that these screens work..

if not then there will be a few angry customers 😮

that's what I meant: On Yosemite it looks like all the HD4000 Mac's have also received an driver update (system/extensions). Now right now checking if the .kext stuff could be reverted to use old (Maverik HD4000 Driver)...however. not an easy task, because normally the Graphics is very close to Apples OS...

HD4000 graphics problems when using a very big external screen

going to try this solution, will post if it worked

Okay.... I managed to exchange the drivers on Yosemite (with Maverick HD4000 Drivers) ...now I do have 3440x1440 on Yosemite (and 34UM94) from my MacMini - however: I got now the scrambled lower part of the screen. So thanks FrediMac: Will check out these instructions next.

(I used "kext utility 2.5.7" to swap the graphics drivers).

So I now followed the Instructions from the mentioned post and it worked for me :-) HAPPY AS CAN BE - hopefully this is a hack that lasts, but I don't think Apple will update this kext-file very often - what do you think?

Hi Fredi

Question: Did you use "Maverick" Drivers or did you just patch the Buffer File?

I patched with the Buffer File with "old Maverick" Drivers, which was even worse than with the scrambled lower part...

I don't know exactly why - but when putting back Yosemite Drivers (but still keeping old Maverick Buffer .kext) it worked too

Yosemite working fine on MacMini (2012) on HD4000 with 3440x1440 50hz

Would someone be so kind as to actually post the modified driver files? I upgraded to Yosemite and don't have a Mavericks backup available right now.

Such a dumb problem to have.

I asked this question myself (why is nobody uploading this file?) and when I thought about it, I realized that the .kext File has to match your exact machine. "Playing" with .kext Files is very "dangerous" - my previous attempt crashed my whole system. I would suggest that you try this hack on a fresh installation of Yosemite on an external harddrive, and if it works, use it on your real system (with all files backuped - just in case!).

Wish you all the best!!

Regards,

Frederic

Hmmm, well I triedd the instructions and not very successful at all. I modified the buffer memory in my kext file and still no dice. If anything performance is worse. Utter disaster.

It ***** that I bought this expensive monitor that was working fine and not it isn't. I'm going to have to see about getting Mavericks back on which is terrible.

I'm not sure what others did to get this to work, but I modified the kext file in AppleIntelFramebuggerCapri and refreshed the cache and nothing.

ah well I do have 3440x1440 on my last reboot, but not I have the garbled and jumpy distorted video on the bottom of the screen.

thanks for posting 😀