Daisy-chaining 5 displays with DisplayPort

vv211

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Oct 6, 2011
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I'm doing some work for a restaurant that is using 5 NEC P463 TVs (1920x1080 native resolution, set up in a single row) to display their menu items. Their previous set-up was a tower that was using, iirc, 3 nVidia GTX 460's with DVI -> HDMI adapters to output to the displays.

I suggested switching over to something that I thought would be much simpler (and require less cabling): A single Radeon R7 260X using its DisplayPort to daisy-chain the displays, the owner could then sell the old equipment and make his money back (he's decided to hold onto the old setup as a backup though, leaving all the old cables in place)

The new setup is: R7 260X DisplayPort out to 1st display in the series, each subsequent display is daisy-chained thereafter, and the motherboard's DVI port out to a KVM switch in the office to a monitor there

The issue I'm having is that with the P463 displays daisy-chained, CCC is seeing them as a single 1920x1080 display, and they're all showing a duplicate image. I looked around in the display's OSD, and found a setting to switch between DisplayPort 1.1 and 1.2 (default is 1.1). I switched it over to 1.2 and the first display stayed up, while the other 4 in the chain went black and CCC gave me a message saying that I was trying to use more displays than it supports.
I broke the chain, so that only the first and second display were daisy-chained to the GPU and still had that message showing up with the second display still dark.

I called NEC and they instructed me to use their LAN daisy-chaining, use the DisplayPort 1.1 setting, and to set up a tile matrix with the displays. This makes CCC still see all 5 as a single display, but they all share an image/desktop (ie, the 1920x1080 display is shared across them, essentially making each individual display show a 384x1080 image).

This display wall is something I can work with, but 1920x1080 wouldn't cut it (I'd very much prefer the 9600 horizontal resolution that the combined displays are capable of), so I Google'd for ways to set a custom resolution on a dispaly. I tried using the CRU (custom resolution utility) tool, the PowerStrip tool, and changing the "DALNonStandardModesBCD1" setting in the registry. CRU and PowerStrip wouldn't let me go to 9600, and changing the setting in the registry did not give me the option to select that resolution in Windows after I rebooted. I was, however, able to get to 3840x1080 with CRU

Stretching the menu images across the 3840 horizontal resolution looks *ok*, but not quite enough to make the owner happy.

So, I'd like some help either getting the display wall to show at a 9600x1080 resolution, or to use extended desktops, with separate control over each individual display in daisy-chain. I read that daisy chain supports a max of 4 displays at 1080p, so I could just break the last display from the chain if need be and hook it up to the HDMI port on the 260X

Thanks for any help :)