Processor or RAM causing slowness?

Question

Calling all speed demons...
OK.. so I just got a new Quad Core single 3.2 GHz processor Mac Pro with 6 GB RAM to replace my aging 2006 2 x 3GHz 8 Core Mac Pro and was told at the Apple Store not to be fooled by the one processor and 6 GB RAM versus my 2 processor 8 core machine as the new components are much faster than in my old MP, plus my old buss speed was only 1.33.
My experience in the first week has been this machine rocks. But I've been doing easy stuff, like Word and Excel files and email.
But tonight I'm working on a large sound file of a friend's band that is a MP3 of 10 songs, which I am using Audacity app to copy/paste and create 10 separate MP3 song files and noticing extreme sluggishness. Luckily I don't do this for a living and I don't do any video or serious Photoshop rendering either.
When I select a section of the large MP3 file that equals one song, it takes up to 30-45 seconds for the MP to calculate or whatever it's doing, and then I copy and paste into a new file and save the single song as a new MP3.
I'm wondering if the sluggishness is due to only having one 3.2 GHz processor, or only having 6 GB RAM.
Of course I'm hoping the issue is RAM as I can control that and buy more, versus having to trade up to a 12 core MP which is expensive and way more computer than I really need on a day to day basis.
I don't know if it's possible for readers here to comment on this, but if you can... I'd love to hear any theories and solutions.
Thanks,
Steven

Answer 1

It's a bit complicated, but you may want to read some of this material:
About OS X Memory Management and Usage
Reading system memory usage in Activity Monitor
Memory Management in Mac OS X
Performance Guidelines- Memory Management in Mac OS X
A detailed look at memory usage in OS X
Understanding top output in the Terminal
The amount of available RAM for applications is the sum of Free RAM and Inactive RAM. This will change as applications are opened and closed or change from active to inactive status. The Swap figure represents an estimate of the total amount of swap space required for VM if used, but does not necessarily indicate the actual size of the existing swap file. If you are really in need of more RAM that would be indicated by how frequently the system uses VM. If you open the Terminal and run the top command at the prompt you will find information reported on Pageins () and Pageouts (). Pageouts () is the important figure. If the value in the parentheses is 0 (zero) then OS X is not making instantaneous use of VM which means you have adequate physical RAM for the system with the applications you have loaded. If the figure in parentheses is running positive and your hard drive is constantly being used (thrashing) then you need more physical RAM.
Adding RAM only makes it possible to run more programs concurrently.  It doesn't speed up the computer nor make games run faster.  What it can do is prevent the system from having to use disk-based VM when it runs out of RAM because you are trying to run too many applications concurrently or using applications that are extremely RAM dependent.  It will improve the performance of applications that run mostly in RAM or when loading programs.