What is a reasonable execution time?

[eluser]smilie[/eluser]
Hm, everybody goes like: 2 or 3 seconds I would wait...

I would live to see a script that would convert video of 100+ MB in 2-3 seconds :-)

As TS said: it is CMS.
For CMS page load (user experience) should not be more then 2-3 seconds - I agree.
However, if user in CMS uploads a 250MB movie, which then needs to be converted - exec time of couple of minutes would be reasonable

Regarding perfomance check - Firebug + page speed does wonders as well :-)

Cheers,
Smilie