Connecting Inspiron 7720 laptop to two 1440p monitors

Just came across this old post. What I ended up doing is connect one monitor in 1440p through the HDMI port and to the other one in 1080p using the VGA port and a VGA-to-HDMI adapter that I got off of Amazon. I wasn't able to get a 1440p resolution out of the VGA port unfortunately.

Hi Bilalm, please can you tell me how you got 1440p working via hdmi for the 7720? I would dearly like to be able to do that. My research has led me to conclude, although the GT650M is easily capable of handling 2560x1440p, the hdmi port may not by 1.4a compliant and/or the the primary intel GPU is the limiting factor being the primary GPU.

Your solution would be most welcome.

The only way to get another 1440p display connected to that system would be to use a DisplayLink adapter, which is essentially a USB 3.0 to HDMI adapter.  However, displays attached by DisplayLink adapters do not behave the same way as displays connected to actual display output that are directly controlled by the GPU.  I've already written about how DisplayLink works and possible side effects in multiple threads here, so I'm not really interested in doing it again, especially as the original question was asked months ago, but you should be able to learn more with a little research.  I will add that one less obvious caveat to DisplayLink is that if your system has switchable graphics (i.e. both Intel and discrete GPUs), the discrete GPU will not be able to accelerate graphics on DisplayLink-attached displays, due to a Windows limitation.

quick update. It works! Tried switching out the amazonbasics cable for different one and got 2560x1440p but max 35Hz. still, it worked! But I still feel that the way the hardware is configured, sadly we cannot use the full potential of the GT 650M

You're correct about the Intel GPU being the main limitation here.  In almost all laptops that have a discrete GPU that have been made over the last few years, the discrete GPU is not actually wired to any display outputs.  It operates as a render-only device that passes completed frames to the Intel GPU, which IS connected to the outputs.  This happened basically when Intel started building GPUs right into their CPUs.  There are some very high-end laptops like the Precision 7000 Series models that have BIOS options to let the discrete GPU take direct control of the display outputs, which is necessary to take advantage of technologies that the Intel GPU doens't support, such as stereoscopic 3D, 5K displays, VR, G-Sync, etc.  However, that capability requires a more complex and expensive motherboard design, and those needs are fairly rare, which is why that option is only available on high-end laptops geared for specialized work.

VGA will definitely not handle 1440p.  HDMI should as long as it's HDMI 1.4, but I haven't looked at the specs of the Intel GPU in your system to confirm.  The fact that you got it working but only at 35 Hz is unexpected, but in that case depending on your intended use case, you may prefer to use a DisplayLink adapter.  The ability to have 1440p @ 60 Hz might be more valuable to you than the tradeoffs involved with DisplayLink-attached displays.

Thanks jphughan, I feel like trying to get 2560x1440 on an external monitor seems to be a wild goose chase. However many people claim to have done it. Reading further as mentioned above my understanding is that without a display port, all video going through hdmi and vga (even if using the discrete GT 650M) still go through the primary integrated HD 4000 and hence the 1080p limitation. If anyone can provide a working solution I will be grateful.

ps. I've tried custom resolution via the integrated HD Graphics Control Panel with no luck. My next step was to try to disable the integrated graphics chip but this seems to be a hardware limitation and the GT 650 does not take up the role of primary GPU.