This is my script for testing the pi's overclocking stability.
It displays the cpu temperature while performing three simultaneous tasks:
Initially, it only used dd (hence the declared variable dd_pi_stress_level=1); change this value to increase the stress level.md5sum < /dev/urandom &
cat /dev/urandom | gzip > /dev/null &
dd if=/dev/urandom of=/dev/null bs=16M &
The script is probably in need of "some" polishing.
Yeah, I know, not quite like a "Quake stress" killer, but it is my script. It was fun building it.