While at a trade show this week, I learned something new about AMD's professional GPU line up: they support virtual displays. Well they have for awhile in the sense that you can take two physical displays and combine them into one logical monitor via Eyefinity. However, what I witnessed was the opposite of Eyefinity: the ability to logically add a connected display that would appear as a virtual picture-in-picture window on a physical monitor. This was exposed to the OS as a regular window and could be moved and scaled as appropriate. Each virtual PIP window appeared as a physically connected display to Windows for orientation and spatial layout (i.e. what monitor border would you move your mouse across for the cursor to appear in the virtual display).
It is genuinely a niche feature that has a handle of niche applications. First use-case is that it enables developers to experiment with odd ball resolutions that they may not have access to. 3840 x 2160 resolutions displays are relatively common place right now but the ultrawide 3440 x 1440 units less so. Thus a developer can create a 3440 x 1440 virtual display that fits neatly inside the larger 3840 x 2160 display without having to worry about the display itself scaling the image or flat out lacking support for the lower resolution.
The second use-case is that some displays are simply becoming too high of resolution to work well with some legacy applications. Some applications actually break when they encounter a display wider and/or taller than 4096 pixels. This is due to how EDID originally worked allocating 12 bit (4096 possible values) for indicating the number of pixels vertically and horizontally. Legacy applications allocated their own internal display logic in adherence to what was being reported via EDID which means the same 4096 pixel limitations. A lower resolution virtual monitor can be created to handle this applications and then the PIP window can be full screened. This will not have the greatest image quality due to scaling involved but it does a better experience in many cases.
The last use case I can see is enabling logical picture-by-picture or similar arrangements on a single display that doesn't support that feature natively. Alternatively this could emulate picture-by-picture-by-picture to make an ultra wide appear as if it were three displays (technically four since there would still be the host display underneath everything).
Regardless, this is an interesting feature that helped me work around a 1920 x 1080 resolution limitation of a demo using a VDI session that would display a massive border on a higher resolution monitor.
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