displayport splitters

[OhYou_]

hello. 

what are some downsides of using displayport hubs as splitters?
At my work I have two 1440p monitors I use at my desk, but I am setting up a workbench nearby which is a standing desk. 
I want to put two monitors of equal 1440p resolution there and a second set of mouse and keyboard, then simply split the displayport of each screen to run both at once, simply turning off the displays on my desk and turning on the ones at the workbench. 

 

But will it cause problems or noticeable lag?

[tkitch]

no lag that you'd actually notice.  

just make sure the splitter actually supports 1440.

[Eigenvektor]

3 minutes ago, tkitch said:

just make sure the splitter actually supports 1440.

The GPU also needs to have enough bandwidth on the one port you're using to support 2x 1440p. As long as the GPU has at least DisplayPort 1.2 you should be fine.

[OhYou_]

2 minutes ago, Eigenvektor said:

The GPU also needs to have enough bandwidth on the one port you're using to support 2x 1440p. As long as the GPU has at least DisplayPort 1.2 you should be fine.

bandwidth should be the same because the image is just mirrored to each display? I was hoping actually that it doesnt and the mst hub will just fallback to mirroring mode. I actually dont know how mst hubs handle mirroring, if it is treated as two separate streams entirely and I have to mirror it in windows. 

 

I know for sure that mst hubs fallback to mirrored mode on hardware that does not support 1.2 or mst. idk how its handled otherwise. 
I could switch to hdmi but thats probably a disaster since the source has only one hdmi port, but two dp 1.4 ports

[Eigenvektor]

Just now, OhYou_ said:

bandwidth should be the same because the image is just mirrored to each display?

Ah, I thought you wanted to have two independent 1440p displays, not mirrored. I suppose it shouldn't require the bandwidth for two monitors if you're mirroring, but I don't really know. But if the card has DP 1.4 as you say, bandwidth shouldn't be an issue for 2x 1440p.

[OhYou_]

also another consideration is i will be using two 17.3 portable monitors since there is nothing between 17.3 and 23.8in and it must be 1440p to match the current screens for mirroring. 

no idea if this matters since it will just use displayport since it is type-c input but i really hope it doesnt get weird when the portable monitors are switched off.

[tkitch]

11 minutes ago, Eigenvektor said:

Ah, I thought you wanted to have two independent 1440p displays, not mirrored. I suppose it shouldn't require the bandwidth for two monitors if you're mirroring, but I don't really know. But if the card has DP 1.4 as you say, bandwidth shouldn't be an issue for 2x 1440p.

The GPU is outputting to one display.  The splitter is splitting the signal to two places.

 

No need for extra "bandwidth"

[Eigenvektor]

9 minutes ago, tkitch said:

The GPU is outputting to one display.  The splitter is splitting the signal to two places.

 

No need for extra "bandwidth"

Yeah, what I meant is the card is technically outputting to a 5120x1440 display, the splitter then splits it to 2x 2560x1440p. So you need the bandwidth for 2x1440p as opposed to just 1440p. But as I said above, I assumed OhYou_ wanted independent monitors, not mirrored displays.

[OhYou_]

4 minutes ago, Eigenvektor said:

Yeah, what I meant is the card is technically outputting to a 5120x1440 display, the splitter then splits it to 2x 2560x1440p. So you need the bandwidth for 2x1440p as opposed to just 1440p. But as I said above, I assumed OhYou_ wanted independent monitors, not mirrored displays.

yeah, does it do that even when mirroring? I assume so if its mirrored in windows but i really dk

[Eigenvektor]

3 minutes ago, OhYou_ said:

yeah, does it do that even when mirroring? I assume so if its mirrored in windows but i really dk

Yeah, I'd assume it would if it's mirrored in software, but if the splitter does it in hardware, it shouldn't.