Entire Mac slows down every day, especially if more than one user logged in

Question

Mac runs fine at the start of each day (after turning it on), but slows down by evening. iPhoto is typically at a crawl at that point, and I can't have more than one user logged in at a time, or the whole system takes forever to do anything. I've restarted, repaired disk, repaired disk permissions, run Cocktail, checked for viruses (VirusBarrier). It's easy to restore normal speed with these moves, but same problem every day. I have 24 GB left on this hard drive--is that too little?
Should I try erasing hard drive and restoring from Time Machine? Should I reload Mac OS X from discs?
Advice much appreciated. Thanks.

Answer 1

Robert Fishman1 wrote:
I have 24 GB left on this hard drive--is that too little?
you do the math
this will help:
Your Mac needs adequate hard drive space to operate normally. How full can a drive be before it's too full? There is no hard and fast rule that says “X” amount or “%” of free drive space is needed. A low amount of RAM requires more drive space for Virtual Memory’s swap files.
Problems from insufficient RAM and free hard disk space are discussed in this link
http://www.thexlab.com/faqs/lackofram.html
Here’s some general guidelines for minimum hard drive free space:
1. As a general rule, your available space should be 5GB as an absolute minimum as it generally requires that much free space to perform an Archive and Install of Mac OS X and still preserve some free space for VM swap files.
2. Some say that your hard drive should have at least 5% of it's capacity available for use. Still others say 10% to 15%. If you routinely process complex graphics and videos, even more space is required.
Look at these links about freeing up more space.
Where did my disk space go?
_*http://www.macfixitforums.com/showflat.php?Cat=&Board=Forum38&Number=770243*_
Download & use WhatSize described in this link or Disk Inventory X @ _*http://www.derlien.com/*_
Freeing space on your Mac OS X startup disk
_*http://www.thexlab.com/faqs/freeingspace.html*_
Amazing Disappearing Drive Space
_*http://www.pinkmutant.com/articles/TigerMisc.html*_
Increase HD Free Space
_*http://macosx.com/forums/howto-faqs/275191-how-easily-increase-hd-free-space-lap top.html*_
How to free up my disk space
http://www.macmaps.com/diskfull.html
JGG