Bezel Management Calculation [NV Surround/Eyefinity]

[kryptokatalyst]

I recently joined the NV Surround ranks and when setting up the bezel management I quickly desired something more accurate than "by eye." I've done a lot of searching and found nothing comprehensive to explain how to determine the exact number of pixels between the viewable area of the screens.

As such, I decided to do the maths and create just such a guide, which would mathematically determine the number of pixels required for precise bezel management with any setup. I haven't used Eyefinity, but I hypothesize it will work there as well. (Confirmation/denial from Eyefinity users appreciated.)


LEGEND:

x = Horizontal Resolution (given be Manufacture)
y = Vertical Resoltuion (given by Manufacturer)
z = Diagonal Resolution (to be calculated)
S = Screen Size (diagonal measurement given by Manufacturer)
PPI = Pixels Per Inch (to be calculated)
D = Distance between Monitors (to be measured)

SQRT = Square Root​

First we need to calculate the Diagonal Resolution(z) for the monitors:

z = SQRT( x^2 + y^2 )​

Example: 23" LCD @ 1920x1080​

z = SQRT( 1920^2 + 1920^2 ) = SQRT( 3,686,400 + 1,166,400 ) = SQRT( 4,852,800 ) = 2202.90717008​

Secondly, we use the recently calculated Diagonal Resolution(z) to determine the Pixels Per Inch(PPI):

PPI = z / S​

Example: 23" LCD @ 1920x1080​

PPI = 2202.90717008 / 23 = 95.7785726123​

Third, we need to measure the distance(D) between the viewable areas in inches. The best way to do this is to place two of the monitors directly next to each other at the same angle, then measure. I recommend using a soft measuring tape or a small plastic ruler to reduce the risk of possibly scratching a screen.


Lastly, use the measure distance(D) and the Pixel Per Inch(PPI) to calculation the number of pixels to be used in the bezel management settings:

Number of Pixels = D x PPI​

Examlpe: 23" LCD @ 1920x1080 w/1.5 inches between viewable areas​

Number of Pixels = 1.5 x 95.7785726123 = 143.667858918 --> Rounded to 144 pixels​

Using the above steps we have calculated the number of pixels to be used for bezel management to be 144.


NOTES:
- This guide only works with monitors of the same size and same resolutions
- It is recommended to avoid rounding until after the final calculation