Q: More RAM?

There are lots of reason why a mac might be running slow.  You have addressed on my cleaning up the harddrive.  

Look at what is happening with your Mac when you run Activity Monitor.

Macintosh-HD -> Applications -> Utilities -> Activity Monitor

1) Be sure you select all processes in the double arrow selection just be low the window title line.

2) Click on the CPU tab on the lower half of the window to see how much time you are using and if any applications are hogging the CPU.

3) Be sure the triangle in the CPU title is in the down position.  This will list the processes from high to low.

You can gain some understanding of Activity Monitor by  looking at it every once in a while.  Look at the small graph.

Here is how I have my CPU display set up:

Do you need more cpu memory.

Click on System Memory to get statistics on memory usage.  You should have some free memory.

The number to look at is page outs.

Mine is 13397. This means that some of my programs and data had to be written to disk because cpu memory filled up for a time.  It means my programs ran a little slower than they could have.  I could run fewer programs, deal with the slowness, or buy more memory. I'd say you want at least 512meg of memory for 10.4.

If the entry for entry for Page ins/outs is:

Page ins/outs: 29163/0

Notice I have 0 pageouts which says that I am not using my harddrive for extra memory space.  Thus, I have enough memory.

Activity Monitor has a neat feature where it can display a dynamic dock icon.  In Activity Monitor View > Dock icon > Show cpu history.

"Reading system memory usage in Activity Monitor :"

http://docs.info.apple.com/article.html?artnum=107918

Managing Memory

See   Kappy

http://discussions.apple.com/message.jspa?messageID=8025223#8025223

Problems from insufficient RAM and free hard disk space

http://thexlab.com/faqs/lackofram.html