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What is the difference between DP Alt Mode and USB-C/DisplayPort Combo?

Rehan_Nell
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Good day to all my fellow Tech Enthusiasts. I am at a loss with getting a USB-C Dock(J5 Create JCD543) to work with a ASUS TUF FX506LH. I am trying to connect 2 Large NEC displays over HDMI with the dock while providing USB and network function over the Type-C 3.2 Gen 2 port but only the one HDMI port next to the VGA and the VGA port works, the DisplayPort/HDMI port does not put out a display. I have tested this dock on Thunderbolt 3 and works on all ports even without the driver. I contacted ASUS and they told me the laptop does not support(have) DP Alt Mode but is has USB-C/DisplayPort Combo. What is the difference between the two? If it is that the Dock is not compatible with the laptop, what full size dock would work on this laptop that has USB, Network(RJ45) and 2 HDMI outputs?

20220303_202702.jpg

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52 minutes ago, Rehan_Nell said:

Good day to all my fellow Tech Enthusiasts. I am at a loss with getting a USB-C Dock(J5 Create JCD543) to work with a ASUS TUF FX506LH. I am trying to connect 2 Large NEC displays over HDMI with the dock while providing USB and network function over the Type-C 3.2 Gen 2 port but only the one HDMI port next to the VGA and the VGA port works, the DisplayPort/HDMI port does not put out a display. I have tested this dock on Thunderbolt 3 and works on all ports even without the driver. I contacted ASUS and they told me the laptop does not support(have) DP Alt Mode but is has USB-C/DisplayPort Combo. What is the difference between the two? If it is that the Dock is not compatible with the laptop, what full size dock would work on this laptop that has USB, Network(RJ45) and 2 HDMI outputs?

20220303_202702.jpg

Is the dock you are trying to get to work a thunderbolt dovk or just a "regular" USB-C dock? As far as I know, Thunderbolt docks don't eork that well on non-thunderbolt ports. I have managed to get 2 display outputs workimg on my non-tb dock on both a non tb and a tb port

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13 hours ago, DreamCat04 said:

Is the dock you are trying to get to work a thunderbolt dovk or just a "regular" USB-C dock? As far as I know, Thunderbolt docks don't eork that well on non-thunderbolt ports. I have managed to get 2 display outputs workimg on my non-tb dock on both a non tb and a tb port

DreamCat04, here is the link to the product https://info.j5create.com/collections/full-docking-stations/products/jcd543. It does not specify that it is Thunderbolt and you get 2 Models: One that has Power Delivery Passthrough and one without it and I have the one without power delivery.

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5 hours ago, Rehan_Nell said:

ASUS and they told me the laptop does not support(have) DP Alt Mode but is has USB-C/DisplayPort Combo. What is the difference between the two?

Those two things mean the same.

The USB Type C specification is very broad and includes alternative modes ('alt mode'), one of these is Displayport alt mode. That means the USB Type C includes Displayport functionality, so there is no difference between those two things.

 

The only thing I can think of what is happening is that your laptop is setup so the USB Type C port put out video from its built-in Intel HD Graphics and not the Nvidia graphics card, but even then it should at least output video.

Maybe there is some incompatibility with MST; the technology that allows one Displayport connection (whether through USB Type C or another connector) to output to multiple monitors, but if that is the case, no USB Type C hub for multiple monitors would work.

 

Maybe you could live with one monitor connected through the dock and the other connected with HDMI to your laptop?

 

P.S. Be sure to quote people when replying to them, that way they get a notification you replied. The quote button is the arrow-button underneath their post.

"We're all in this together, might as well be friends" Tom, Toonami.

 

mini eLiXiVy: my open source 65% mechanical PCB, a build log, PCB anatomy and discussing open source licenses: https://linustechtips.com/topic/1366493-elixivy-a-65-mechanical-keyboard-build-log-pcb-anatomy-and-how-i-open-sourced-this-project/

 

mini_cardboard: a 4% keyboard build log and how keyboards work: https://linustechtips.com/topic/1328547-mini_cardboard-a-4-keyboard-build-log-and-how-keyboards-work/

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7 hours ago, minibois said:

Those two things mean the same.

The USB Type C specification is very broad and includes alternative modes ('alt mode'), one of these is Displayport alt mode. That means the USB Type C includes Displayport functionality, so there is no difference between those two things.

 

The only thing I can think of what is happening is that your laptop is setup so the USB Type C port put out video from its built-in Intel HD Graphics and not the Nvidia graphics card, but even then it should at least output video.

Maybe there is some incompatibility with MST; the technology that allows one Display Port connection (whether through USB Type C or another connector) to output to multiple monitors, but if that is the case, no USB Type C hub for multiple monitors would work.

 

Maybe you could live with one monitor connected through the dock and the other connected with HDMI to your laptop?

 

P.S. Be sure to quote people when replying to them, that way they get a notification you replied. The quote button is the arrow-button underneath their post.

Sorry I am new to this Tech forum. I can display out to two monitors from the HDMI and VGA at the same time but the Display port on the dock does not display out or the second HDMI port but all ports work over Thunderbolt 3(Probably 4 as well). The problem is actually with my supplier as they say the laptop does not support DP Alt Mode and thus the dock Display Port won't work but The Specs says differently. Neither the dock nor the Laptop supports MST but I am only trying to display to two screens and not three thus MST is not needed under my knowledge of the MST feature. 

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On 3/15/2022 at 12:03 AM, Rehan_Nell said:

Sorry I am new to this Tech forum. I can display out to two monitors from the HDMI and VGA at the same time but the Display port on the dock does not display out or the second HDMI port but all ports work over Thunderbolt 3(Probably 4 as well). The problem is actually with my supplier as they say the laptop does not support DP Alt Mode and thus the dock Display Port won't work but The Specs says differently. Neither the dock nor the Laptop supports MST but I am only trying to display to two screens and not three thus MST is not needed under my knowledge of the MST feature. 

Personally I wasn't aware of MST only being relevant for 3+ monitor setups.

But anyways, USB Type C with Displayport inside is DP Alt mode, so It's still a strange way for ASUS to respond. 

"We're all in this together, might as well be friends" Tom, Toonami.

 

mini eLiXiVy: my open source 65% mechanical PCB, a build log, PCB anatomy and discussing open source licenses: https://linustechtips.com/topic/1366493-elixivy-a-65-mechanical-keyboard-build-log-pcb-anatomy-and-how-i-open-sourced-this-project/

 

mini_cardboard: a 4% keyboard build log and how keyboards work: https://linustechtips.com/topic/1328547-mini_cardboard-a-4-keyboard-build-log-and-how-keyboards-work/

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