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My Macbook Pro (unibody, mid 2009, 13") supports the 1920x1200 resolution of my screen, using the VGA display port adapter, but when I connect that through a simple USB + VGA KVM, the resolution becomes limited to 1920x1080, ruining the whole experience.

I'm guessing it happens because the Mac can't figure out what kind of screen is attached to the cable.

Is there a way to work around this?

I've tried SwitchResX but it didn't help. I would add the resolution, but it still wouldn't show up on the list.


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Does your KVM support DDC so that it can receive the EDID data? – user59671 Dec 19 '10 at 1:44
up vote 1 down vote accepted

It's entirely possible that the KVM doesn't support resolutions greater than 1920x1080, or that the VGA<->DisplayPort adapter you have has a maximum resolution of 1920x1080. Most DisplayPort adapters supporting resolutions greater than 1920x1080 require some form of external power.

Really though, 1920x1080 is an insanely high resolution for VGA.

EDIT: Does the monitor work with 1920x1200 when connected directly to the display?

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The monitor works with 1920x1200 through the display port and VGA. I'd use DVI, but this KVM is VGA only... – Andre Oct 6 '10 at 19:29
Oh and the KVM says it supports it on the manual and is powered by USB – Andre Oct 6 '10 at 19:44
Ah.. don't know then :( – Billy ONeal Oct 6 '10 at 19:45

Looks like the KVM switch did not support or store the DDC-EDID information and feed them to your MacBook Pro.

Just a VGA-EDID emulator between KVM switch and the connected system (MacBook Pro in your case). Of cause, before you put the emulator in between, you need have the emulator "clone" the monitor's DDC-EDID.

I have the same setup as you did. I have a MacBook Pro with a Displayport-to-VGA adapter connect to a KVM switch. I fully understand the issue.

The emulator solved the display resolution issue. However, it ended up with upgrade my old KVM switch with new KVM switch which support full-time all DDC-EDID to all connected port after I connected systems to the old KVM.

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I would upvote this if you also added a link to the VGA-EDID emulator that you used. – Paul Wagland Jan 31 '11 at 5:01

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