Using Multiple Displays on a Single Computer
by Keith Lightbody - Facilities Consultant - last updated 5 March 2009

Most users who have made the move to dual displays swear they will never look at a single screen again! Why?

Two smaller monitors are cheaper than one larger monitor so a large display space can be achieved very economically. Improvements in productivity of 10-30% have regularly been achieved by multitasking users (based on both local experience and online research - see Helpful Resources below). Multiple sources of information can be manipulated or integrated easily. Also important is improving accuracy and allowing faster recovery from errors. Setup is reasonable as modern operating systems have built in support for multiple monitors - after 10 minutes most users are comfortable with dual displays. Multiple LCD screens easily fit on a users desk. Some recent graphics cards support single, dual, triple and quad display desktops. Users who spend more than 20% of their time on multiple tasks will find a clear benefit with 2 or more screens.

Some benefits that are possible without minimising/maximising or tabbing/toggling between windows include:
- work in two different applications simultaneously
- see more content at once, immerse yourself in a digital panorama
- make the image larger and easier on your eyes
- extra space to spread out documents for easy reviewing
- make comparisons between multiple information sources
- deal with multiple tool bars, menus or windows
- troubleshoot by performing the steps on one screen with instructions on the other
- read presentation notes while second monitor & projector show only presentation to audience
- view a spreadsheet while writing a report
- make reference to guidelines or notes while collaborating with other users
- view a presentation while following a supplementary web page;
- have all emails in inbox on one screen while working on individual email on other screen
- view a laboratory simulation while following instructions or notes
- see multiple viewpoints simultaneously
- have photograph manipulation software on one screen e.g. CS4 and photo management software on other screen e.g. Aperture, Lightroom
- view a streaming video while reading points on a supporting web page
- help desk situations that require simultaneous viewing of both local and remote desktops
- great for collaborative tasks with 2-3 people
- ... add more ... please email me!

- at least 2 LCD displays, 2 CRT monitors or 1 of each
(while LCD displays are the most space efficient, old CRT monitors are widely available and still very useful)
- usually best to have uniform height for multiple displays (not higher or lower)
- dual head video card (2 outlets - possibly 1 analogue, 1 digital) or 2 compatible video cards
(with two PCI video cards, the one nearest the CPU will boot first, with one AGP and one PCI, the PCI will always boot first).
- configuration as required (possible layouts include left/right, upper/lower, diagonal or other permutations)
Experienced users can change modes as required e.g. from a single wider field of view to multiple views.

Advanced users:
- an all digital signal (PC to graphics card to display) produces better picture quality
(when compared to a digital PC signal converted to an analogue graphics card signal and then converted to digital display)
- also consider use of triple, quad or higher numbers of displays

Helpful resources:
Productivity and Multi-Screen Displays. NEC-Mitsubishi, ATI, and the University of Utah. 2003
(article starts p.31, conclusion p.51, 52)
CineMassive Displays (2-6 screens)
Triple displays
Quad displays
Products available

I noticed a growing trend for certain workers to use multiple computer screens in 2005. I discussed the changes in workflow with many people who regulary used multiple screens. After a month of using dual screens myself I was convinced so I wrote this article. Multiple screens can also be very helpful when two people are collaborating on a single project e.g. cross referencing information simultaneously from multiple screens and multiple sets of printed material. First published online in October 2005. Feedback from Tina Hoyland, Lui Scaldaferro, Robert Kaufman and Darren Atkinson has been incorporated into the above notes. Statistics on usage of this site are gathered by Google Analytics and Chilli Tech web stats.

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