Tiling: Can or should you lose the Video Wall Controller?
I had a conversation with a video wall customer that highlighted significant confusion some users can feel when implementing a video wall. His high resolution content was the simplest possible: a single 4K full screen feed of 4K movie playing from a dedicated PC in a loop for a museum environment on a 2 x 2 array of large monitors.
Were they better off buying 4K monitors or 1080P monitors? What was the simplest and most cost effective video output from the PC to the array? The question of signage monitor tiling came up, and the customer had been confused by prior misinformation. Once they understood the issues at hand, they chose an array of 1080P monitors able to tile 4K input.
Typical Video Walls:
Typically Video Wall Arrays are built with 1080P monitors connected to a PC video card with multiple outputs, to a hardware video wall controller, or to a software video wall controller like Userful’s. The bigger the array, the more wires and configuration options are available. There are excellent reasons to use Userful or other video wall controllers, but tiling might be a good choice if you understand the limitations.
Content is important in your decision:
Sometimes we can avoid the complexities and cost of a Video Wall controller or use of a multi-output video card and the related complexity and cost. Before we evaluate and choose the best option, we first need to understand the limits of the content we will display and also the limits of the controller options we might choose.
Tiling: Input Resolution and Output resolution
Most serious digital signage monitors offer tiling options with single input and a daisy chained array of monitors. Earlier models have generally produced less than satisfactory results because they expand the 1080P (1920 x 1080) input signal to as many monitors as you have in your array. You can manufacture or simulate resolution missing from your input.
Each monitor is assigned an array location at set-up and displays only the proper assigned section of the 1080P signal for that assigned location. A 5 x 5 tiled array of monitors will display each pixel in the 1080p signal at a 5 pixel x 5 pixel “clump” of pixels that may be easily visible. Your array surface may be huge, but your resolution won’t be larger than the original input, so an image viewed from close distances might be grainy.
1080P Full Screen Content as input
If the content input to an array will always be a single 1080P signal displayed full screen, then even the most impressive and expensive video wall controller or monitors can’t improve your displayed resolution. Whether you tile in the monitors or expand in the controller the results will be basically the same. If 1080P will your only content input and will always be output to a full array screen, you will lose display resolution whether you output to a single 4K monitor or an array of 1080P monitors tiled.
4K Full Screen Content
4K inputs might be a single 4K PC monitor output, or perhaps a single 4K output from another 4K source like a 4K Blu-Ray player, 4K AppleTV, etc. If we have 4K content to display, we should have the full 4K monitor resolution from input to screen and be able to display it fully.
A “starter array” of 2×2 landscape 1080P monitors technically has exactly a 4K displayable monitor resolution of 3820 x 2160. If your content is produced and delivered in 4K resolution and will always be displayed full array screen, this seems like a perfect fit.
The newest generations of many digital signage 1080P monitors now offer 4K inputs that can be tiled over daisy-chained arrays, allowing full 4K display at full resolution 4K on a 2×2 Array of 1080P monitors without using a Video Wall Controller.
These monitors also offer bezel compensation via the monitor set-up menus, so you’ve get everything you need to present a full screen, high quality 4K image from a single 4K input without the expense of a video all controller.
Ultra Thin Bezel (3.5mm Bezel to Bezel) 4K input 1080P signage monitors are common and have been dropping significantly in price as I write this.
In conclusion, for the simplest content and arrays, the availability of 4K monitor tiling on 1080P monitors brings reduced cost and simplicity of set-up to 2 x 2 or larger Video Wall Arrays. If your content is single output full screen understand the limitations of tiling, you can make an intelligent decision whether you should use monitor tiling instead of a video wall controller.