electron14 » May 15, 2012

Daily Archives: May 15, 2012


Korean 27″ Displays

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I recently purchased two new 27″ displays from a Korean Ebayer. You can read all about them here and here. ┬áBasically they’re the same panels that are in the nice Apple displays, but they didn’t quite make the cut for one reason or another, so they got sent to obscure Korean manufacturers who sell them in monitors for 1/4 the price.

I purchased Sunday afternoon for $319 each, shipping included, and 48 hours later they arrived. They both look remarkably good, I really had to hunt to find any discernible defect. One has two tiny stuck pixels and the other I *think* is just a hair dimmer than the other, which seemed to go away via brightness adjustment.

Really, though, this post is about how I got them to play nicely with the Nvidia TwinView on my Ubuntu desktop. You see, with the nouveau driver that is loaded by default, one worked fine, but to get the full acceleration and TwinView, I had to install the nvidia module, and for some reason it didn’t want to properly retrieve the monitor’s EDID. The result was a flickering 640 x 480 display; not pretty.

In troubleshooting, I noticed that ‘xrandr –prop’ would get the EDID nicely, but tools like get-edid from the read-edid package would return 128 bits worth of ‘1’s and complain of a corrupt EDID. X seemed to pick up the proper one when running the nouveau driver, and not when running the nvidia driver.

So I fired up a hex editor and pasted the EDID as reported via xrandr, all 128 bytes, and added a custom EDID file to my xorg.conf so the nvidia driver would work with the dual displays.

You can add the following to the screen section of /etc/X11/xorg.conf, just under metamodes or wherever you prefer.

Option “CustomEDID” “DFP:/etc/X11/shimian-edid.bin”

Note you can also do semicolon delimited for multiple displays (or so I’ve read):

Option “CustomEDID” “DFP-0:/etc/X11/shimian-edid.bin; DFP-1:/etc/X11/catleap.bin”

I’m including the QH270 EDID .bin file here, in case anyone is desperately looking for it or having a hard time creating one. It should be similar or even work as a drop-in replacement for the Catleap Q270, aside from the Achieva models.