I will spare you the life story of how I came to want to do this and instead outline what I would like to accomplish:
- One (Windows) desktop computer with a video card that has two HDMI and two DisplayPort ports.
- One (Linux) laptop that has two USB-C Thunderbolt 3 ports.
- Four monitors:
- 1920x1080 60Hz
- 2560x1080 75Hz
- 3440x1440 100Hz
- 5120x2160 60Hz
What I would like to do is connect all four monitors into a KVM switch, and then from the KVM switch, connect all four monitors to both the desktop and the laptop. I would also like at least one USB port on the KVM that I could connect a USB hub to for switching my mouse, keyboard, graphics tablet, etc.
From there, ideally I would be able to switch all four displays and all the peripherals between each device by pressing a single button on the KVM.
However, there are three problems I have encountered with this idea:
- KVM switches are expensive as fuck
- Very few KVM switches support a two-computer, four-monitor [2x4] connection (it is almost always the other way around [4x2])
- The few KVM switches I have found that do support such an arrangement only have DVI ports, no DisplayPort or HDMI
So uh, if anyone knows of any KVM switches (or other solutions) for accomplishing this setup, I would really love to hear about it, no matter the cost.
In this setup, the laptop would be the daily machine, and the desktop would be a dedicated gaming/creativity rig. That gives me some room for alternative configurations:
Because the desktop wouldn't really need access to four monitors, I could get a KVM switch that only supports two monitors [2x2], and then just use something like Synergy to seamlessly move the mouse and other peripherals between computers.
However, I have concerns with how well Synergy would work with a custom mechanical keyboard (running the QMK firmware)(Apparently there are no issues between QMK and Synergy)
Buy two [2x2] switches, which is probably cheaper than one [2x4], and switch all four displays between devices with two button presses instead of one. (And still probably run Synergy for when I want to split displays 2/2 between devices)
Just use a Thunderbolt dock, plug each monitor into the desktop and also into the dock (so two cables coming out of each monitor), and just manually switch the monitors between devices using their input controls. This is probably the simplest option, but switching four monitor inputs can be tedious. Though, I wouldn't actually need to switch all four of them, I could just switch one or two of them, and then use Synergy to take advantage of the others.
Run the desktop headless and stream its video output over the local network to the laptop/monitors. This might actually be the cheapest solution, but input latency would be variable with network conditions and could be a concern. I would also be dependent on specific services for streaming output. Parsec would be my go-to. I have used it before, including with friends over 1,000 miles away, and it works great. However, I'm not too keen on my computing setup being dependent on a single (proprietary) service.