When you run a PowerPC application , it has to use SSE3 , meaning that it will translate dynamically from AltiVec to SSE3 hooks , thus this takes lots of RAM and CPU usage. Plus the performance is not that great. I suggest you to try OSX 10.4.9 , if you have not updated it yet. Try to upgrade the software that you're using or find an alternative if there are no universal binary available for that software

1 use top - You'll got have to use Terminal for it - or use Activity Monitor . Activity Monitor even tells you if its Intel or PowerPC. Pretty handy , if you want to know if a particular software runs on Intel or PowerPC.

2. sudo killall <pid name>/<application name> - Terminal. If you're a GUI Style dude , you can use Force Quit - or press alt + mac key + escape to bring Windows Style Task Manager that allows you to force quit programs


3. Well get Oynx , and System Optimizer X for your system. It updates prebiding , fixes permissions and stuff like that to give some umph to your system. I encourage you to do get it. If you want , you could use the terminal to do it manually.

Not there are not any for it...But you may want to try MenuMeters , {google for it} and install it. You can keep an eye on your memory usage , your HDD activity, your network activity and stuff like that