The speed of 6.1.3 vs 7, 8 or 9

[thehat]

I have developed an app that relies on running 3 animations by showing a stack of cards (107 cards 550 X 400) with a single png image on the card. When I run the app on my 3.2 GHz Intel Core i5 iMac the 6.1.3 version runs pretty fast and on my 2.7 GHz intel MacBook it is fine. If it runs too fast I can easily script it to slow down. When I deploy the 7, 8 or 9 versions of the App to the iMac it is adequate,however, when viewed on my 2.7 GHz intel (early 2015) the 7,8 or 9 versions are PAINFULLY slow.
Interestingly, when played in boot camp on a 2008 2.4 GHz MacBook all versions are blindingly fast. What is issue with the
Mac OS?

Code: Select all

on mouseUp
   local tstack
   local tcds
   local tspeed
   local tnum
   local tnew
   
   set the lockmessages to true
   put fld "stackname" into tstack
   put the number of cards of stack tstack into tcds
   put fld "speed" into tspeed
   put fld "tymes" into tnum

   open stack tstack
   go to card 1
   put tcds -1 into tnew
   lock messages
   repeat tnum times
   repeat tnew times 
      wait tspeed milliseconds
      go next
   end repeat
   wait 1 sec
   go to card 1
    wait 1 sec
end repeat

end mouseUp

Is there anything I can do to speed up 7,8 or 9 on the 2.7 GHz intel MacBook Pro?
Thanks for any assistance

[richmond62]

The years that your Macintoshes were manufactured are not as much of interest as the versions of Mac OS you are running.

If you can attach your stack (or a link to a download) I will try to give it a "whirl" on my "New-fer-you"
Polycarbonate iMac (2006) I bought on Saturday, running Mac OS 10.7.5 (toothless Lion) and see what
"gives".