Run Second Display over integrated graphics

[akuro0804]

Hi

So I have Lenovo Legion Y540. Whenever I attach a second monitor via HDMI to use it as extended display , second display always run via discreet graphics i.e. gtx1650 and  main display (Laptop display) run over internal graphics i.e. intel UHD Graphics 630.

What I want to is run both of my display and second display over the same graphics mostly on intel graphics while working top optimize by Battery life as  I don't have any graphic intensive work.  In vendor provided software named 'Lenovo Vantage' there is setting named Hybrid Mode if is switch it off then both of my display run via GTX 1650, but have no option to do other way around.

So can you help me to do find a solution for that.

 

Note: Query is related to issues Laptop

 

[Kilrah]

The HDMI port would be connected directly to the 1650 so it can't be used without the 1650 running. 

[TudorFinalBosz]

You need two separate graphics ports that come from the motherboard (not the graphics card) to be able to output graphics from the iGPU on two monitors.

Not sure any laptop has that. Even on desktop, only some motherboards have this.

[TudorFinalBosz]

@akuro0804

It might also be possible to daisy-chain two displays and have only one directly connected to the graphics port from the motherboard.

Some displays allow daisychaining. That's probably the only possibility in your case.

[Eigenvektor]

6 minutes ago, TudorF said:

Some displays allow daisychaining. That's probably the only possibility in your case.

That would require DisplayPort though (at least version 1.2, I think), not HDMI.

[TudorFinalBosz]

@EigenvektorYes, I wanted to add this in my reply but didn't bother.

It might also be possible if he has a USB-C or Thunderbolt port which supports video output.

 

Or you could use an HDMI splitter, but that would output the same signal on two monitors. In this case, you could maybe "extend the displays" (in Windows Settings) and have one single video signal output on both displays as if it's one display. It would look weird, especially if you played a game. But for productivity such a setup could work if you resize windows manually.

 

Later edit: Hm, but if Windows doesn't see two external monitors, it probably can't extend displays. So it will just output a single video signal to the HDMI cable which will just output a mirrored image on both displays. So not sure if there's any kind of adaptor you can use over one single HDMI port to output separate signals.

Yeah only Display Port, or USB-C or Thunderbolt could do that.

[Eigenvektor]

8 minutes ago, TudorF said:

In this case, you could maybe extend the displays and have one single video signal output on both displays as if it's one display.

Do you mean like running a wide screen resolution in the hope that the splitter would somehow send half the image to each monitor? Cause that's not going to happen. It would simply send the same wide screen image to both.

[TudorFinalBosz]

@Eigenvektor Yeah, right, I edited my post just now to say that it probably still wouldn't work because Windows couldn't see two displays through that HDMI splitter.

So it could only work if he had another USB-C / Thurnderbolt / DisplayPort that is connected to the motherboard.

[Eigenvektor]

7 minutes ago, TudorF said:

@Eigenvektor Yeah, right, I edited my post just now to say that it probably still wouldn't work because Windows couldn't see two displays through that HDMI splitter.

Yeah, as far as I know, the HDMI protocol doesn't support anything like Multi-Stream Transport (MST), so you can't really run two monitors on the same port (except in clone mode). You'd definitely need DP for that and a monitor with MST support.

[akuro0804]

2 hours ago, Kilrah said:

The HDMI port would be connected directly to the 1650 so it can't be used without the 1650 running. 

How could I verify that ?

[akuro0804]

@TudorFI am using my Laptop's screen as primary display and adding an external monitor connected to with HDMI

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[Kilrah]

1 hour ago, akuro0804 said:

How could I verify that ?

That's the standard design for laptops with discrete GPUs.

 

Having the HDMI port connected to the iGPU would cause performance loss when you want to drive the external monitor with the dGPU, and avoiding that would require extra switching hardware... Since people will typically be at a desk when they use an external monitor and that monitor will need power there's no point going adding that when you can just plug the power adapter making the extra power consumption irrelevant. 

[TudorFinalBosz]

2 hours ago, akuro0804 said:

@TudorFI am using my Laptop's screen as primary display and adding an external monitor connected to with HDMI

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Seems that this laptop does have HDMI, miniDP and USB-C, but the video outputs are probably connected to the graphics card.