Performance degradation. Need advice on starting all over again.

Question

I have never formatted my drive or reinstalled my OS X like I used to do with XP during the windows days. Now there is some performance degradation and opening of applications like Safari, iPhoto and others is really slow. I maintain Time Machine backups of my full Snow Leopard partition. What should I do? Format the HD, re install SL, or simply restore from TM or reinstall and then restore...?
I dont really want to carry my windows attitude to mac, of reformatting, reinstalling and then starting all apps from scratch. I wanna leverage out of my TM backup. Please advice.
Neerav
MacBook 2.4GHz Unibody (Late 2008), 2GB RAM, SL

Answer 1

The hatter wrote:
Those steps, repair permissions? only checks the installed application receipts -- worthless.
Disk Utility doesn't check for bad blocks, and Apple First Aid misses and doesn't fix directory problems that are picked up by 3rd party tools like Disk Warrior.
The hatter's comments do not represent a consensus of opinion about this & are at least partially misleading.
Permissions repairs are indeed limited to comparing receipt info to actual permissions settings, but that is hardly worthless. It is well documented that mis-set permissions will cause a number of problems & resetting them to receipts values is an effective cure for those specific problems. Obviously, that won't cure problems with other causes, but since there is no magic cure-all it would be foolish to expect it to behave like one.
Regarding Disk Utility, it is true that it can't repair certain problems that some 3rd party utilities can; however, it is very effective at identifying file system problems, including those for some file systems the 3rd party apps do not support. It is also the most conservative disk utility available, designed not to attempt any repair that could result in loss of data. This is one reason it isn't as powerful as the 3rd party ones -- it is best to use it first if you suspect you have file system problems & use the more powerful ones only when necessary.
To be fair, Disk Warrior includes a directory optimization function that Disk Utility doesn't. However, an "unoptimized" directory isn't a problem in & of itself, & it is debatable how much real world benefit there is to optimizing the directory, at least with the current OS & modern high performance drives. I used to see noticeable improvements by periodically using Disk Warrior with OS 9 & the drives of that era, but these days my Macs & Snow Leopard seem to do just fine without it.
Basically, it is simple: use the tool that best does what you need to do. There is no benefit from using a sledge hammer when a tack hammer will do; in fact, the sledge hammer may do more harm than good, or just wear you out for no good reason. Also consider the wisdom of the old saying that to a hammer everything looks like a nail. Sometimes, you don't need a tool at all, just the wisdom to know that you don't.
Regarding bad sectors, every drive has them. That is not a concern by itself but the drive suddenly developing new ones is a sure sign of serious problems. Drives keep track of this themselves. Utilities provide a way to query the drives about this & may provide early warning of impending failure, but since the drive is providing the info this is not 100% reliable. For this reason, whether you use one or not, it is extremely important to backup your important data to other devices regularly & often.