2560 x 1080 Not Available on Mac Pro Early 2008 With ATI Radeon HD 5770

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Level 1

4 points

2560 x 1080 Not Available on Mac Pro Early 2008 With ATI Radeon HD 5770

I have 4 monitors hooked up to Mac Pro early 2008 via 2 video cards. One card is ATI Radeon HD 5770 and one is ATI Radeon HD 2600 XT.

I have a new Samsung 29" Ultrawide SE790C monitor. I hook it up to the HD 5770 (either with Dual-Link DVI cable to monitor via DVI-to-HDMI adapter, or from HD 5770 MiniDisplay port to HDMI via adapter).

The best resolution that shows up for the monitor is 1080P (1920 x 1080). It should recognize that the monitor AND card can handle up to 2560 x 1600, but I can't get it to do so.

Any ideas?

Mac Pro, OS X El Capitan (10.11.1), Early 2008

Posted on Nov 16, 2015 8:45 AM

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Answer 1

lllaass

Level 10

210,411 points

Nov 16, 2015 8:57 AM in response to jacksbr

I suspect your HDMI adopters do not support greater than 1080p. You need an adopter like discussed here.

LG 2560x1080 monitor with MDP > HDMI

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Answer 2

jacksbr Author

Level 1

4 points

Nov 16, 2015 5:49 PM in response to lllaass

I have Belkin Mini Display Port adapter to HDMI that supports 4K, and HDMI cable that supports it. So no more links in the chain that should prevent it, but still only 1080p shows as an option.

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Answer 3

Nov 16, 2015 7:44 PM in response to jacksbr

That monitor has a DisplayPort input.

Forget those other adapters and buy a Mini DisplayPort to DisplayPort cable, or use the enclosed mini Displayport to DisplayPort adapter with a DisplayPort cable.

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Answer 4

jacksbr Author

Level 1

4 points

Nov 18, 2015 4:20 PM in response to Grant Bennet-Alder

So it must be related to 2008 Mac Pro or HD 5770 Card? Because I can take the same HDMI cable and MiniDisplay port to HDMI adapter and run it off my MacBook Pro 2015 and it works perfectly. Then plug the same thing into Mac Pro 2008 and all I get is stretched screen 1080p.

Does Mac Pro 2008 have a problem with wide resolutions like this? The card is supposed to handle it just fine.

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Answer 5

Nov 18, 2015 6:54 PM in response to jacksbr

In 2008 when that Mac was issued, HDMI was for TV sets, and serious monitors connected by Dual-Link DVI and Mini DisplayPort.

Things changed a bit in the years between that and your 2015 MacBook, and that is reflected by your MacBook taking HDMI a bit more seriously.

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