Sounds like plenty of space on the hard drive. A full hard drive can slow down OSX.
I think more memory can slow down a computer on startup because it takes longer to test it. However, once started things go faster. May be wrong.
Probably some slow down due to having more files, etc. Computer needs to read and write items to cache and directory. Some run system-only partitions to get around having data files sharing same drive as system.
Try doing a bit of spring cleaning by starting up in Safe Mode, then restarting.
[Mac OS X: Starting up in Safe Mode|http://docs.info.apple.com/article.html?artnum=107393]
[What is Safe Boot, Safe Mode? (Mac OS X)|http://support.apple.com/kb/HT1564]
[Safe Boot takes longer than normal startup|http://docs.info.apple.com/article.html?artnum=107394]
[Mac OS X 10.4, 10.5 - Computer shuts down during Safe Boot|http://support.apple.com/kb/TA24054]
Here's a whole bunch of reading on the speed up topic. Not sure if it is all up to date. In particular, avoid the "maintenance" tools unless you know of a specific issue.
[Mac OS X speed FAQ|http://www.macmaps.com/Macosxspeed.html] - general reference on performance in various Mac models
[Tips to optimize your Mac OS X experience|http://www.giantmike.com/speedX.html]
[Mac Tune-up: 34 Software Speedups|http://www.macworld.com/article/49489/2006/02/softwarespeed.html]
[52 Ways to Speed Up OS X|http://www.imafish.co.uk/articles/post/articles/130/52-ways-to-speed-up-os-x>
[Tuning Mac OS X Performance|http://www.thexlab.com/faqs/performance.html]
[11 Ways to Optimize Your Mac's Performance|http://lowendmac.com/eubanks/07/0312.html]
[The Top 7 Free Utilities To Maintain A Mac.|http://mac360.com/index.php/mac360/comments/thetop_7_free_utilities_to_maintain_amac>
[Mac OS X: System maintenance|http://discussions.apple.com/thread.jspa?messageID=607640]
[Macintosh OS X Routine Maintenance|http://www.macattorney.com/ts.html#Anchor-31774]
[Kappy's Personal Suggestions for OS X Maintenance|http://discussions.apple.com/message.jspa?messageID=8230024#8230024 ]
[a brody's Topic: Myths of required versus not required maintenance for Mac OS X|http://discussions.apple.com/thread.jspa?threadID=1772235]
[Are the desktops cluttered with files and folders?|http://discussions.apple.com/thread.jspa?messageID=7668937] and [related comment|http://discussions.apple.com/message.jspa?messageID=9168594], and [here|http://discussions.apple.com/message.jspa?messageID=10434647]
[Problems from insufficient RAM and free hard disk space|http://www.thexlab.com/faqs/lackofram.html] and more details on this [http://discussions.apple.com/message.jspa?messageID=11476663]
Limnos has given you some excellent recommendations. Your computer should be flying along with 4 GB of RAM and Leopard. I have a computer just a bit older than yours and it runs fabulously.
Make sure your data is backed up, just in case.
Get SMART Utility here:
Run the utility & let me know if you get anything other than a "Passed" result.
I've gone through the boot up and shut down in safe mode. I'll continue now working through the list and seeing if I can get the MacBook running any quicker.
As for the smart utility I downloaded it and ran it. Came back with passed.
I shall report back once I've gone through the remainder of the list previously posted.
thanks for all your help so far.
well i've given most of the suggestions offered to me a go and unfortunately I can't seem to still get my MacBook running up at the speed it was previous.
Could this be a battery/power issue? My battery is slowly dying and is no longer holding its charge for as long as it used to. could this be a cause to the slow running?
yes it recognises the installed 4GB of RAM and the status states its 'ok'.
i've just upgraded to Snow Leopard and run another repair disk permissions and the system is now noticeably quicker! hooray!!!
its also freed up some HD space, although that wasn't too much of an issue as before I was only using at most 40GB of 160GB!
looks like for the time being its gone back to normal. i thought it could have been my battery as the system does seem to go through the charge quicker then when it was new however the condition report on my battery is 'good condition'.
so for now it seems like its solved. let's hope it stays this way!
thank you all who have contributed in helping me resolve this situation!