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Question

multiple monitors

Aug 30, 2016 10:52AM PDT

Hi,

I want to use three monitors, one laptop screen and two external screens. I have connected the screens in two ways.

VGA + DisplayPort to HDMI
With this setup, two monitors do work. When I try to add a third monitor (Control Panel\Appearance and Personalization\Display\Screen Resolution) and click OK, Windows gives the following message: "Unable to save display settings".

Wether I enable the laptop screen with an external screen or two external screens does not matter. It just cannot handle three screens. Microsoft says:

"This issue occurs because some laptop graphic adapters only support two displays at one time. When you attempt to configure the display settings to use a third monitor on a laptop that supports only two monitors, Windows 7 and Windows 8 will check the hardware to confirm compatibility, then display the error message."

But the hardware does support three monitors...

VGA + DisplayPort to VGA adapter (to VGA of course)
When i connect the screens like this, alle screens are working. The only problem is that when I set the resolution of the screen attached to the DisplayPort (to VGA adapter) to 1920 x 1080, the screen starts to flicker.

When I put the resolution to 1600 x 900 the screen works just fine. This is not a big problem, but when you buy a 27 inch Full HD screen you want to use it to it full capibility as you can imagine.



I read something about active DisplayPort, should that do the trick? Do I maybe have to 'trick' Windows so it lets me use all three monitors? Or do I just have to live with this flaw?

Thanks for your help!



HP Elitebook 8540w (no HDMI slot)
ATI FirePro M5800

Discussion is locked

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Answer
While I've seen this kicked around before
Aug 30, 2016 11:16AM PDT

I find some get stuck on "should work" versus "reality." I can't see the display model number that is flickering to check out basics. At the end of the day you either go with what works or DEMAND the maker supports you or you return the non-working product.

Again, I can't guess your take on all this but at the office we go with what works as we have no time or more exactly the clients will not pay for hours and days chasing vendors and makers to correct issues.

In this scenario I'd check my VGA refresh rate and specs on that unknown monitor first.
After that I'd get some USB to HDMI/VGA video card and get the job done.

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I forgot to mention
Aug 30, 2016 12:49PM PDT

I forgot to mention that I also tried a USB to VGA with the same result that the screen starts to flicker at high resolution.

The two external screens are a BENQ GW2750 and GW 2760S.

How do I check my VGA refresh rate and what do I have to do next when I got it?

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Could not find the model.
Aug 30, 2016 1:08PM PDT

BenQ GW2760HS 27-inch VA panel HDMI LED-lit Monitor ? Maybe? I only check out specs once I get the model number right. No reason to guess.

The first one is off too but a google seems to guess it's the "BenQ GW Series GW2750HM Glossy Black 27" 4ms (GTG) HDMI Widescreen LED Backlight LCD Monitor".

FIRST, the following is not meant to upset you. I don't own or have access to your machine so I can't be specific.

Moving forward.

The 2750 seems to be OK with other than 60Hz but I would never push it. As to controlling VGA rates, that's all in your video card or laptop driver. It varies so you must look around on your own. Or demand HP document it. HP rarely does since a driver update can cause the docs to go out of date.

The flicker should be retested on another PC driving the monitors at 1920x1080 60Hz. If you go other than the Native LCD panel pixels and refresh rate, odd things happen.