Wednesday, May 20, 2009

How Big Should Large Screen Displays Be In Your Command & Control Room?

Many A/V planners are challenged with how big large screen displays should be in their command & control rooms. There are actually some fairly complicated calculations that can be done which will help you determine what the minimum character size (sometimes referred to as 'x' size) should be under a given circumstance. This 'x-size' is defined as being the height of the smallest coherent element within the presented material. Think of this in terms of a lower-case letter x.

This lower case 'x' - which really is the same height as the smallest of the lower case letters - should subtend not less than 10 arc minutes on a viewers retina to be recognized at any viewing distance. This becomes more complicated when viewers are located off axis to the center of the screen as this requires a larger subtended angle and there is some affect as a result of colored symbols, amount of time the image is on screen, etc. As you can imagine... if you were sizing a screen for projection of a spreadsheet in order to go order to review your Data Center metrics you might want to use these calculations (which can be found in this ICIA publication)

Or a good free presentation on this subject can be found at:

Tuesday, May 05, 2009

Should New York Stock Exchange be hiding the location of its new Data Center?

I find it interesting that major financial institutions & government agencies attempt to hide the locations of their Data Centers. How effective can this non-disclosure aspect of security really be in today's media frenzy world? Obviously not too effective since NYSE's new Data Center build is already being talked about in Data Center Knowledge & The Bergen Record.

Even if details of this site location go unpublished, word from employees & vendors who support this site certainly will spread. I'm not saying that we should broadcast in neon lights the location of this Data Center, but if a new Data Center is constructed covering all 4 disciplines of security {Physical, Operational, Logical & Structural} POLS, will it matter if the public knows where the Data Center is if the security is thoroughly covered. It isn’t likely that the NYSE can really hide the whereabouts of its ~400K square foot Data Center anyway. Most Data Center designers cover Physical & Logical security systems thoroughly as those disciplines are maturing. What is often not covered thoroughly is the Structural Security, organizations become too focused on getting a CO and getting the new Data Center live that they often don’t cover themselves from the structural threats of fire, water, theft & wind.

How many Data Centers are built with a 20 minute fire rated door? How many Data Centers are built with more than a 10-15 minute Class 125 rating? The real interesting aspect to this point is that there are new building materials that can cover Structural Security and omit these unnecessary exposures while actually constructing the facility & obtaining the CO faster.