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U2715H, P2414H, daisy chaining
I'm having "similar" problem with daisy chaining U2715H REV A.05 (Nov 2017). I have recently bought a U2715H and I want to daisy chain it to my old P2414H (REV A.06, Oct 2015).
When I connect my old rig with Gigabyte GTX 760 OC 2GB (DP/DVI-I/DVI-D/HDMI) via DP to DP on U2715H, and enable DP 1.2 to connect to P2414H via DP, the resolution on U2715H drops to 2048x1152@60Hz and P2414H works on native resolution 1920x1080@60Hz.
If I disable DP 1.2 on U2715H then on P2414H I get (of course) the message: "The current input timing is not supported by the monitor display. Please change your input timing to 1920x1080, 60 Hz or any other monitor listed timing as per the monitor specifications."
After all combinations with cables, driver updates (currently on last driver 398.11), problems with custom resolutions, refresh rates (to reduce bandwidth), etc. I realized that I haven't tried DP-->mDP because my rig is ~3m away from desk and my monitor setup. I pulled it closer to connect and tried. And this worked but don't know why.
I connected PC via DP > to U2715H mDP (in) --> DP to DP (on P2414H) and I got the full resolution on U2715H 2560x1440 @ 60Hz (native) and full resolution on P2414H. For that I used the mDP-DP cable supplied with U2715H.
I tried different DP(m) to DP(m) cables. 2m, 3m, 10m (certified DELOCK 4K 10m and 3m, up to 3840x2160@60Hz, DP cable 2m supplied with P2414H). But only option that works for now is when I connect PC via DP to mDP on U2715H (2m long) --> DP to DP on P2414H.
First I thought that it was the GTX 760 bandwidth (max digital resolution 4096 X 2160), cable length, cable bandwidth 3840x2160@60Hz
Gigabyte GTX 760 (spec): https://www.gigabyte.com/Graphics-Card/GV-N760OC-2GD-rev-20#sp
10m cable: http://www.delock.com/produkte/S_84862/merkmale.html
Do you know which type mDP-DP cable is supplied with U2715H? 1.2, 1.4?
I was thinking to get one more U2715H, but now I'm not sure.
I know this is old thread, but if you can, please answer to my dilemma(e).
DELL-Chris M
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June 23rd, 2018 15:00
Our monitors were only tested/validated with the supplied cabling =
P2414H RN698 2m/6ft DP 1.2 DP to DP cable
U2715H 05VX0 1.8m/5.9ft DP 1.2 DP to mDP cable
Longer cabling was never tested. But the usage of longer cabling will cause a drop in resolution. If this configuration works, then we know the 3rd party and longer cabling were the problem =
PC DP out port --> U2715H DP to mDP cable --> U2715H mDP in port (DP 1.2 Enable)
U2715H DP out port --> P2414H DP to DP cable --> P2414H DP in port
murrrawi
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June 25th, 2018 10:00
Chris,
Thank you for quick a answer. My suspicion was also on that matter that lenght maybe was a culprit.
And yes now I checked, supplied cable for U2715H is 'only' 1.8m (not even 2m as DP-DP supplied with P2414H)! :))
So that goes for the argument that lenght is tested and working, and 0.2m more in lenght and signal is gone (crazy).
But I also tried to daisy chain with supplied cable (mDP-DP 1.8m) to connect my refurbished Lenovo Thinkpad W540 (nvidia quadro K1100M, W10 pro, 3K native on laptop display) -- mDP (out) --> DP (in) U2715H --> P2414H and it didn't work. Also didn't work with longer cable (supplied with P2414 nor 3m, or 10m ofcourse).
Now I think maybe it's due to k1100m output capabilities, or 1.2 DP compatibility and bandwidth, but... since I couldn't check that for now I tought to order longer DP-->mDP cable (5meters) and report back if daisy chaining is possible or not.
Now, I don't know if that is even an option since your statement about tested lenghts.
Other possibilites are:
1. HDMI cable "distance" test (since there is a HDMI out on GTX 760). I think DL-DVI cable with DP/HDMI adapter wouldn't work (?).
2. An upgrade of 760 GTX with some other (newer) card with minimum 2xDP (out) ports to accomodate two U2715H via two long cabels, as 10m DP cable works for sure for 2K.
For me the distance / lenght of at least 5m is a need, but will manage for now to work with current solution:
DP->DP (PC-U2715H), DVI->DVI (PC-P2414H)
Best regards, and thank you again for an answer/direction!
M
DELL-Chris M
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June 25th, 2018 10:00
HDMI out on the GTX 760 could only work for HDMI to HDMI cable or HDMI to DVI-D cable. Possibly HDMI to HDMI cable to HDMI to DVI-D adapter. Not sure if they would have the same issue with long cables.
murrrawi
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June 25th, 2018 21:00
Also not sure about HDMI lenght issues.
But I will try that and will report back after I order some long cables and before I even think to buy another U2715H. Not a quick way of finding things now since they don't have them locally and longer cabels usually are a bit more pricy. It may take a while to give a feedback but when I get some answers I will.