Q: How to display 2560x1080 on external monitor from MBP or MBA?

I have the EXACT same monitor.

Basically:

HDMI to Mini-Displayport cable would work but not at correct resolution.

Displayport cable plus the hama adapter (https://www.hama.com/00053245/hama-3in1-mini-displayport-adapter-for-dvi-display port-or-hdmi-) would not be recognized by the Computer.

Normal HDMI plus the hama adapter would work the same as a HDMI to Mini-Displayport, i.e would detect but no option for the correct resolution.

The ONLY thing that worked was (and I found this out by accident after trying to fix it for around 9 hours straight):

WORKING SET UP: NORMAL HDMI CABLE and NORMAL DISPLAYPORT CABLE BOTH PLUGGED IN TO THE MONITOR AND BOTH CONNECTED TO THE MACBOOK AT THE SAME TIME THROUGH THE HAMA ADAPTER LINKED ABOVE.

The Display option on the monitor is set to DisplayPort. You can get there by going to the moniter menu and choosing the input (click the monitor button, then choose menu on the left, then click Easy control, then Input, then go to DisplayPort.

Like I said, I have the exact same moniter, I have a Macbook Pro and it is working FLAWLESSLY with the working set up.

That helps a lot thank you!

My only question now is that you said " NORMAL HDMI CABLE and NORMAL DISPLAYPORT CABLE BOTH PLUGGED IN TO THE MONITOR"  but how do you plug the displayport cable into the monitor when there are only 2 HDMI ports?

I really appreciate the help!

OH SNAP mate I am so sorry I didn't realise I have the LG 25UM65 not the LG 29UM65-P!! My Monitor has a displayport input at the back!!

HDMI did not get me to the correct resolution at all for Mac, no matter how much I tried.

I just looked for a HDMI (Male) to Displayport (Female) adapter but I dont think it exists...theres one on Alibaba (Ecommerce website) but not sure how reliable the description is because from what I've just read it needs some sort of converter.

I think your only option is SwitchResX (the program which you can download here http://www.madrau.com/srx_download/download.html) which I couldn't get working but I am not a hardware tech guy at all so apart from a few guides and instruction on this thread (first page) I couldn't get it to work properly.

Theres also an app called Display Menu (https://itunes.apple.com/en/app/display-menu/id549083868?mt=12) but I'm not sure if it allows you to set up custom resolutions.

Other than that I recommend returning the monitor and getting the LG 25UM65 and using the fix I used. But I might be wrong as I said I am not a tech guy so perhaps someone with better knowledge can give you better advice.

Really sorry mate I know how frustrating it is as I went through it myself! But worth it once you get it working!

APPLE NEED TO TAKE NOTE AND MAKE ULTRAWIDE RESOLUTIONS AVAILABLE AS PART OF THEIR MAIN SETTINGS!! IT WOULD SAVE LOTS OF PEOPLE LOTS OF HASSLE!!!!!

Ya it's been super frustrating! Ive called everyone and apple directed me to your post haha

I think I'll just have to return it. What a hassle.

Thanks for your help, I'm sure I would've wasted a few more hours and $ if you didn't help!

No problem buddy! Yep real hassle over something I didn't think would be an issue in this day and age! Its really disappointing especially when you are excited to have a new monitor!

Defo less hassle to return it and get something you're sure that works. If you come back home tomorrow with an LG 25UM65 , a displayport-displayport cable, a hdmi-hdmi cable and a 3 in 1 Displayport/HDMI to Mini Displayport adapter like the Hama one i posted, in theory you should be good to go!!

Good luck with it mate!

EDIT: BTW the cable the guys in this thread are referring to is one like this http://www.amazon.com/Monoprice-32AWG-Mini-DisplayPort-Cable/dp/B0034X6SCY

I never tried this! Maybe it will work without the adapter and hdmi! But just saying! Im not taking any chances though lool

THIS FIXED IT FOR ME! Thank you so so much! After tinkering with this for 4 days, I'm so incredibly appreciative. Thanks!!

What fixed it for you? The solution from Lord Farz Wolf which he posted on Nov 5, 2015 10:57 AM?

I also bought the LG 25UM65 and I spend many hours already, looking for a solution and spend lot of money on all different kinds of cables, so I don't want to spend a lot more for a solution, but I'm willing to try the adapter, if you say this works.

Thanks in advance!

No. I was attempting to reply to an earlier comment and it didn't work out. I was replying to genriquediaz's comment onJun 20, 2013 4:00 PM. Anyway, after posting my reply on this thread a fellow troubleshooter confirmed a better solution. Myself and another reddit user spent a few days attempting to work this out. Our final conclusion was that this cable just works. No need for ScreenResX. Just plug and play: http://www.amazon.com/gp/product/B00VMFPO1W?psc=1&redirect=true&ref_=oh_aui_deta ilpage_o00_s00

Not sure why but, after "downgrading" to Yosemite, the wide screen monitor is recognized and working fine.  Not sure if this got fixed with a Yosemite patch or if having it plugged in while installing fixed it. 

Very confusing

Thanks Emeryshores! So if I understand correctly the devil is in the 4K cable?

Because I live in Holland, I'm not going to buy the cable of your link (shipping costs) but I'll manage to find a 4K cable around here.

It doesn't need to the exactly this cable. any mDP <> DP cable should work just fine. I never had any issues using mDP cabled on my MBPr.

I have my mac mini (medio 2011) connected to my LG 25UM65 using a mdp <> dp cable at this very moment and everything is very blurry, so your statement is not completely true.

Blurry? Can you take a picture of this? I have never seen a blurry screen which is digitally connected.

No need to look for a 'normal DP' or 'normal hdmi' cable. By following the instruction here: http://www.tonymacx86.com/graphics/175973-solved-el-capitan-2560x1440-hdmi-ga-h9 7-d3h-hd4400.html, I was able to use a mDP-HDMI cable on LG 25UM56-P monitor for 2560x1080, without even using SwitchResX.

For res 2560x1080 on my Acer 21:9 aspect ratio monitor helped this instruction http://surajms.com/2015/04/fixing-switchresx-saving-issue/

and latest SwitchResX

Good luck