Late 2008 Macbook Pro - Spinning Beachball - Why?

Question

Over the last few months I've noticed a rapid decline in the performance of my macbook pro. I've used it to produce music on it without issues so it should still be quite a capable machine. At first I thought it might be my new WD 750Gb scorpio black hard drive but I've since reverted back to my original factory hard drive and the problem is the same. I have been using CCC rather than doing a fresh install so I don't know whether doing a fresh install will help. When I first started out I have leopard - is Lion or Mountain Lion (which I currently run) more processor intensive? I get this spinning beachball often when I'm not doing anything particularly heavy on the cpu. When opening apps and sometimes they don't respond and when I click launchpad sometimes the icons are blank until it has time to visually update them. Ableton often takes up to 5 mins to open but its usually about a minute or so these days. I've reparied all permissions, verified hard drives, reset my PRAM & SMC and tried 2 different hard drives. The battery is on 'replace now' and I notice it may be swollen as sometimes it intereferes with my trackpad functioning (clicking). My 250GB hard drive has about 40gb free on it too as I tried deleting things to free it up. The decline of the battery may coincide with the decline in performance but I can't say for sure if they are related.
I know my laptop is old now but it was working prefectly not that long ago. Is there any kind of log or screenshot I could post to give you more information to help?
2.8Ghz Intel Core 2 Duo
4GB 1066 MHz DDR3 RAM -
NVIDIA GeForce 9400M 256 MB
OSX Mountain Lion 10.8.4
Thanks,
Pete

Answer 1

My 250GB hard drive has about 40gb free
Empty the trash in the Dock as well as iPhoto’s trash!
Open up your application folder & go through all your apps.  Trash all the apps you no longer want and/or use.
An easier way to do this is to open the Application folder in list view & press the Command+j keys.
In the the dialog that appears, click the "This Window Only" button & the "Calculate All Sizes" check box.
Wait a bit until your file & folder sizes have all been calculated, then click the "Size" column to sort your apps from the fattest to the most anorexic.
Get rid of all your photo files you don't want and/or need.  Same goes for those pics off the websites you downloaded (gifs, jpegs, etc.).  Or transfer/move them all to a photo/movie storage site like ImageShack and Photobucket, 2 of the most popular  FREE  storage sites.
Get rid of all your video & music files you no longer view and/or listen too.  Especially, if you already have the actual CD/DVDs or you can later redownload from a website.  Or transfer them all to a FREE video/movies and/or music storage site.
Use Spotlight to make sure you got rid of everything.  You can even trash directly from Spotlight!  Better yet, download this FREE software called Find File.  This app puts Spotlight to shame (works w/Mountain Lion).
Drag what you don't want and/or need to the trash.  Better yet, download this neat little shareware app *demo* called AppZapper.  It basically does all the work for you by not only trashing the apps but the apps preference files, caches & all its associated files.
Another software that does the above is AppDelete.  Best of all this software is free!
Burn what you want and/or need onto CDs or DVDs. Not everyone has the  luxury of purchasing an external HD and/or the system requirements for iCloud to store their "stuff.”
Dropbox is a free storage utility to check out.
You can check with your ISP to see if they offer *free* storage space.  Most if not all do now-a-days.   There are thousands if not millions of *free* storage facilities on the web also.  Use your favorite search engine to search them out as they come in different storage sizes to fit your needs & wants.
Check for duplicate fonts.
Applications>Font Book
Select “All Fonts”
If you see any “black dots” next to any fonts this mean you have duplicates and/or multiple versions of these fonts.
To clean this up, select a “black dotted” font or the Apple + *click* to select multiple dotted fonts;
Edit>Resolve>Duplicates.
What the above does is turns off the duplicates & multiple version fonts.  Not delete them.
More than likely the “extras” were installed by other programs and/or other users.
Clear out font caches
Use FontNuke.  It does all the work for you.  And, best of all it’s *FREE*.
Printer Drivers
Get rid of all the printer drivers you don’t need & use except the ones for your *current* printer(s)/scanner(s).
HD>Library>Printers Folder
If you accidently threw something out that you needed for your printer/scanner it can be easily obtained from the manufacturer’s website and/or from the CD that came w/the printer/scanner.
Garage Band
Has about 1GB of loops stored.  Get rid of some some them.  You surely don’t use, like and/or need them all.
HD>Library>Audio/Apple Loops>Apple>Apple Loops For GarageBand
Or just get rid of the Garage Band app altogether if you don’t use it.
Get rid of extra languages
Strip your computer down to your “native” tongue.
You can do this with a *FREE* utility called Monolingual.  Another app that apparently does all the work for you.  I’ve never used it.  However, a lot of users here swear by & recommend it highly.
However, there is a warning for *native English speakers*. Make sure you keep BOTH English and English (United States).
Other Resources:
HD Space Checkers:
Disk Inventory X (FREE)
WhatSize (SHAREWARE)
OmniDiskSweeper (FREE)
GrandPerspective (FREE - donation)
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Mac Performance Guide
Slimming your hard drive
Rule of thumb: You should never let your hard drive get to where you have only 10-15% of space left.
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The battery is on 'replace now' and I notice it may be swollen as sometimes it intereferes with my trackpad functioning (clicking).
You should not be using your computer until the battery is replaced.  If it is indeed swollen and/or leaking, it will cause serious internal damage.
Have you tried the following?
Mountain Lion Recovery
Boot up from your computer by holding down the command+r keys.  This will take you to the recovery drive.
Select Disk Utility & hit Return. 
In Disk Utility select the HD on the left & click on Repair Disk (bottom right).