(I asked the same question over in the HP Support Forums with, probably, way too much detail. No responses.)
I'm able to dock my HP ProBook 640 G1 on the HP 90W and extend my screen to two external monitors (via DVI and VGA) while still powering my laptop screen (so, my graphics card can power 3 screens in total). But I'm not able to duplicate my laptop screen to an additional external monitor via displayport. What do I need to do to get this setup right? I've heard that I can't do both DVI and displayport, either or. So in that case, do I need to buy a device like this Plugable USB to DVI/VGA/HDMI Video Graphics Adapter and plug into the USB port on my dock?
- Laptop System Model: HP ProBook 640 G1
- Processor: Intel(R) Core(TM) i5-4300M
- OS: Windows 7 64-bit (SP1)
- Docking Station: DIB HP 90W Docking Station
- External Monitors: Planar PLL 2410W (I have three of them. They each have a DVI and VGA connection)