displaying numerous large image files quickly

[Mark Swindell]

I'm working on a simple game of concentration for the kids I teach.  

I have 24 small image rectangles grouped on a card that are populated in a repeat loop which sets their fileNames to line x of a list of filenames held in a variable.  These files can be large images.

lock screen
put the seconds into vSecs
repeat with x = 1 to 24
    set the filename of image x of group "imageGroup" to line x of vPopulate
end repeat
unlock screen
put (the seconds - vSecs)

The above takes 5 seconds (which is close to an eternity...)

Is there a faster way to make this happen, or should I simply make a progress bar and not worry about it?  

Thanks
Mark