can I beat firefox over the head with a stick for a bit?

[Tsakali]

is there any way i can decrease a specific program's processing power?

I want to see how playback suffers on different setups.

Priority / Affinity has anything to do with this?

[creep]

Priority/affinity only decrease the relative power apps get when multitasking. If the cycles are going idle, any app will get them.

If you're wondering "Can I tell this app it's running on a p3-500" or "Can I limit this app to X cycles/second" then no, I know of no way to do that.

[creep]

You may have some limited success with running a cpu stressing app (prime95, folding@home, etc) at a notch higher priority than firefox... but that'll likely end with ff doing nothing while the crunching app eats your cpu for breakfast.

[Tsakali]

I guess I can try hardware underclocking but I'm sure the apple wont fall too far from the tree.

[MKJ]

there are apps that slow down your proc to simulate certain obsolete specs. typically used to run old games in somewhat normal speeds..

might be able to find something on 'abandonware' sites ?

[Tsakali]

will do

[R00k]

You could also try installing a couple of virtual machines on your PC, and run the app in a VM while using a different, CPU-intensive app on your main installation.