they can't.
I don't knwo if migrate to an other script will solve your problem. My solution was (is) totally rewrite 4images, and it's only finished 25-30% untill now, but i have great results.
For example, when 130 users are online the index.php opens in about 2-3 seconds (26 queries) - before we start the changes it was about 25-60 seconds, sometimes even timeouts.
My programmer says, when the changes are all done i can expect more than 500 users browsing with less than 60% CPU and server load under 3-4. I'am now on a Dual P4 3,2Ghz and 2GB RAM.
Changes will be done in 20-30 days, so then i can post the final results of my (hard) modified version.
Greetings