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U2414H, daisy chain, last using DVI-D/VGA/HDMI?
I just wanted to confirm whether it was possible to daisy chain two monitors if the last monitor in the chain only had a DVI-D/VGA/HDMI port, but the other end of the cable was still a DP. The exact setup is as follows:
Surface Pro 2 --> mDP to DP cable --> U2414H DP in port
U2414H DP out port --> DP cable to DVI-D/D-SUB-LG E2442T or an LG TV (supporting DP cable to HDMI)
Or does daisy chaining only work if the second monitor has a DP in port? Which I think is the answer but I just want someone to confirm that for me.
jphughan
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September 22nd, 2020 19:00
@Tobyha No, that is not correct. Normally, a daisy chain requires DisplayPort signaling along the entire chain. The use of an active adapter allows you to bend this rule, but only for connection that feeds the last display in the chain. A passive DP to HDMI/DVI adapter or cable would not be usable. A DP to VGA adapter MIGHT be usable since all DP to VGA adapters are inherently active, since DP has never had even optional support for sending a native VGA signal the way Dual Mode DisplayPort allows DP outputs to send native HDMI/DVI signals. But VGA is limited to 1920x1200 and is also an analog signal, which means that it will look noticeably worse than any other option, since all of the other options are digital.
jphughan
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September 22nd, 2020 14:00
@Tobyha The answer is "both". Daisy chaining requires native DisplayPort signaling along the entire chain. But when dealing with the LAST display in the chain, if you get an active DisplayPort to DVI/HDMI converter, you can get away with it. The reason is because the active converter allows the system and all displays in the chain except the last one to maintain native DisplayPort signaling throughout, because the DP to HDMI conversion is happening inside the adapter feeding the last display, rather than an "upstream" display in the chain being expected to send a native DVI/HDMI signal through its DP output, which it can't. And the reason it only works for the LAST display in the chain is because a display that receives a signal over HDMI/DVI can't continue the chain. If you're in the US, this is an example of the type of adapter you'd need. I recommended that exact adapter to someone else here, and they replied back confirming that it worked.
Most DP to HDMI cables and adapters are passive, and they only work when the source DisplayPort output supports "Dual Mode DisplayPort", which allows a DP output to fall back to native HDMI/DVI signaling. Most DisplayPort outputs support that, but not all do, and that capability cannot be used in a daisy chain.
Tobyha
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September 22nd, 2020 15:00
If I understand what you're saying correctly, as long as the first monitor in the chain has a display port output socket, then the second monitor can be connected via a display port to HDMI/DVI-D/D-SUB cable without the need for an active adaptor?