Is there a way to manually tell OS X to allocate additional resources to processing for an app?

Question

I know that in some cases, opening up multiple instances of an app will get the job done, but I'm looking for a way to essentially tell OSX:

"If I'm running a process that will take awhile, and there is still plenty of 'room' to go around (in terms of available CPU/RAM/etc...), go ahead and allocate more resources to that app/process so it can finish sooner, as opposed to having a lot of the available resources just sitting there in case I start doing something else and need 'space.'"

Answer 1

You can use the renice command in Terminal to modify the scheduling priority of a running process.

First, find the PID of the process using Activity Monitor, or the ps command in Terminal. For example, if you want to renice Quicktime Player, enter the following command in Terminal:

ps -A | grep QuickTime

This will print something like this, where 7997 is the PID:

7997 ??         8:23.86 /Applications/QuickTime Player.app/Contents/MacOS/QuickTime Player

Then execute renice (it must be run as root):

sudo renice -20 7997

-20 is the most favorable scheduling priority.

Answer 2

No. OSX, like pretty much any modern OS allocates all resources that a program wants, if they're available. Pretty much the only exception is Windows XP, which keeps memory free. But that particular bug was fixed in Vista.