Mac Pro (Early 2009) not fully working with LG 25UM65 2560 x1600

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mijimij Author

Level 1

8 points

Mac Pro (Early 2009) not fully working with LG 25UM65 2560 x1600

I have an Mac Pro (Early 2009) with ATI Radeon HD 4870 512 MB OSx 10.10.3 and an LG 25UM65 2560 x1080 monitor

there is a 4.5cm x 2.5cm black border around the full res image,

I am also running switchResX 4.5.1 as well which says my resolution is 2560 x 1080

am using a mini display port to display port lead,

have tried using a HDMI to dvi but only goes to 1920 x 1080 stretched, but full screen

before boot up the Grey boot screen is full screen but 1/4 way thought the loading bar its goes smaller again.

please help..

Mac Pro, OS X Yosemite (10.10.3), LG 25UM65 ULTRAWIDE 2560 x 1080 monitor

Posted on Jun 26, 2015 3:13 AM

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Answer 1

lllaass

Level 10

210,405 points

Jun 26, 2015 9:37 AM in response to mijimij

What output on the video card and input on the monitor are you using?

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Answer 2

NGEast

Level 1

0 points

Jan 10, 2016 1:23 PM in response to mijimij

Don't know if your'e still looking for a solution, but this is a solution for anyone trying to drive a monitor at 2560x1080 or 21:9 using the original GT120 in an '09 Mac Pro. The monitor I'm using is the LG 25UM56. The GT120, while supposedly supporting the resolution, will not output it for whatever reason if you're in OSX 10.10. My guess is that it is a driver issue. I replaced my video card at first with PNY GT 720, and while it worked for a little it eventually caused my Mac Pro to stop booting and give a restart error. I replaced it with a MSI GTX 660 and have had no issues since. It does require power from one of the 6 pin connectors on the logic board however, and some other manufacturers of the 660 may need two. Hope this helps anyone searching for a solution to the problem I had!

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