Have a HP Elitebook 850 G2. Got a Matrox Triplehead2go Digital.
Updated the firmware on the Matrox TH2G Digital from the Matrox website.
http://www.matrox.com/graphics/en/support/drivers/download/latest/
Connected 1st DVI out to my projector's HMDI input with both a DVI to HDMI adapter and a HDMI cable as well as a DVI to HDMI cable.
Tried the exact same steps with VGA adapter and cables as well.
The problem: can't get any resolution with 3 monitors/projectors higher than 640×480.
1) The Matrox Compatibility tool said my notebook's GPU supports resolutions on it up to 3* 1280×720
Matrox website says the resolution in VGA mode can go much higher than 3*640×480 in VGA mode too:
http://www.matrox.com/graphics/en/products/gxm/th2go/digital/
And my Matrox TH2Go Digital SE supports up to 3* 1280×1024 so I believed the program. But when I connect this version of Matrox TH2G (Digital) via VGA cable (notebooks don't have DVI out mostly) the resolution is automatically set to 1920×480 (3* 640×480) which is too low.
Yes, I have set projector mode to "Extend".
Can't set higher resolution in the GXM program too.
Matrox Support refused to offer any real help and based on the below picture simply claim that my laptop is somehow outputting DisplayPort through VGA port and not a "proper VGA" signal.
I gave them the reason below why that's not the case but they ignored and repeated themselves, and have not since responded to me:
I can connect to a VGA monitor which was made before DisplayPort was invented. If a DisplayPort signal was being sent to the monitor which doesn't support DisplayPort signal via VGA cable, I don't understand how it would display anything. The whole idea that the VGA port was used on this laptop to send DisplayPort for some reason doesn't hold up very well to me. It would be odd, even more so because the laptop has a separate Displayport 1.2 port as well and can be connected to a "HP PowerDeck" which has on itself 2 DisplayPort ports and one VGA (the one's on the laptop itself are then disabled/inactive).
I believe this test was enough by itself but I also made a different test: I connected the laptops DisplayPort port to an active DisplayPort to VGA adapter, then that to TH2G's VGA input and it was still being detected as DisplayPort. I can also use this adapter to connect my laptop to a VGA monitor via its DisplayPort port, not VGA.
What I want to know is why I can't get Matrox Triplehead2Go Digital to work with this laptop, that is, why doesn't it seem to work in VGA mode on Intel HD Graphics 5500 GPUs?
Does It really somehow send DisplyPort signal through the VGA port even though it has a dedicated DP++ port?
If not, what else might be the problem?
And even if the VGA port is limited on these GPUs, why doesn't an active DP to VGA adapter work? I know the DP++ port on the PC can go up to 3072×768 because I've used a different Matrox product on this laptop which uses DP as input. Why is it still recognized as "DisplayPort(TM)" connection in the Matrox's "GXM" software? Perhaps the program just checks the GPU type via the USB connection it requires and simply makes an incorrect assumption?
Has someone else with this Intel GPU family tested this device? Perhaps this is an issue with this specific Matrox TH2G Digital or damaged firmware/software?
Best Answer
According to the intel spec (and applies to VGA too)
That's the max on the shared link. If you divide that by 3 you get 640 max width per panel. Then at 4:3 that gives 480 on the vertical. You won't be able to go any higher on an analogue interface, the DP version is what you need.
Update: Utilizing your DP port instead of the limited VGA you can keep the Matrox unit by going DP->DVI-D->Matrox 3Way
Example: Amazon