"How do I defrag my mac?" "You don't need to, it does it itself" Fragmented Free Space: 99%. READ THIS NOW

Question

Just a heads up for my fellow Mac users.
"How do I defrag my mac?"
"You don't need to, ever. It does it automatically."
"But it's running really slowly..."
"Repair permissions or something. Defragging is not necessary on a mac."
Techtool pro is now defragmenting my mac. Looks like the job's going to take about 4 hours. I thought I'd give everyone the truth about this while waiting (on a different computer obviously)
The truth is, Apple's defragmenting system ***** BALLS. It has two massive, massive flaws which I feel people urgently need to be made aware of.
#1: It only defragments files up to 20mb. If you're a movie producer, a songwriter, a photographer, or anything which involves working with many massive files, the built in defragmenting program WILL NOT HELP YOU IN THE SLIGHTEST.
#2: It only defragments FILES. Free space is ignored, which eventually causes absolutely hrrendous problems.
Let me give you an analogy here. Imagine your mac's hard drive is a bookcase with lots of books on it.
File fragmentation is when it can't find a gap in the bookcase big enough for the entire book, so it breaks the book into pieces and srotes them in different gaps.
Space fragmentation is when there are gaps all over the bookcase, instead of all the books being pushed to one side so there's a long gap elsewhere.
Apple's built in defragmenting program will only fix the first problem - and even then, it will ignore any book bigger than 20 pages long, if you have bigger books which are broken up, you're screwed.
Why is space fragmentation a problem? It's a problem because it directly LEADS TO file fragmentation. If there is a large block of free space all in one part of the disk, then an entire file can be written to it. However, if there is no single free block big enough for the file, it HAS NO CHOICE but to fragment it.
So basically you might have 5 GB free and want to save a 2GB imovie project. That's cool. But what you may not realize is, the biggest single area of free space is only say 600MB. Others are around 300 and 400. Therefore the file MUST be fragmented into all these different areas, which wouldn't be necessary if all the free space was in one area of the disk.
But apple's built in tools don't do anything about this, at least not in Tiger. PErhaps this has been fixed in later installations but I'm almost certain the same issues exist in leopard.
Your only option is to buy a defragmenting program. I know this ***** but believe me, this IS something you NEED to do if your activity on your laptop involves disk space - intensive projects. I'm using TechTool Pro which has been recommended to me as hands down the best. It has a number of other functions as well, right now I'm only using the defragmenting tools but it has others for repairing damages disk sectors and other mantainence tools. There are other programs such as iDefrag out there as well.
Why am I telling you this? I'm telling you because I experienced mind numbing frustration trying to get answers from the Apple community. Google it or ask the question yourself and you will most likely be whacked in the face with the intro to my post here - "You don't need to, it's not necessary, macs do it themselves, blah blah blah"
Even worse, Apple's own webpage on the subject is nothing short of a disaster. It basically says "You PROBABLY don't need to defragment, unless you work with large files." That's it. You'd expect it to have an extra section saying "If you DO happen to work with large files, here's what you do" but no such section exists. It basically says "You don't need to defrag most of the time, and on the rare occasions when you do, well, too bad, you're screwed."
I urge everyone to heed this or they will be tearing their hair out at how slow their mac has become and the fact that no one will offer any meaningful advice other than the standard, generic, "Repair permissions" - the Mac equivelant of "have you tried turning it off and on again".
My disk is at 99% fragmented free space. NINTEY NINE PERCENT. In other words, although I have 25GB of free space, there was not a single contiguous block on the entire machine. I had almost 5,000 fragmented files as well, mostly imovies. Defragmenting got this down to about 300.
The defrag job is taking more than 4 hours and will probably go on to take a lot longer than that. This machine has been slowly grinding to a halt over the last 3 years and now I know why.
Please don't listen to anyone. Get yourself a defragmenting folder, and email Apple to tell them it's just not good enough to give their customers half assed answers and inadequate basic maintainence tools. Mac OS X must literally be the only operating system out there where something as basic as defragmenting is not only almost impossible to get answers on, but actually costs money to fix once you DO get answers.
As customers, we should not accept this any longer. I intend to spread the above message far and wide.
I LOVE Apple. I've always been "a mac" and I always will be. This in no way a mac bashing post or a windows endorsing one. I wouldn't switch back to windows if you gave me a million euro.
But sometimes even the best developers can royally f*ck up. This is one of them.
There is no readon people should be forced to put up with this crap. Absolutely no reason at all. I've had 3 months of crappy performance with no official explanation whatsoever.
Apple if you're reading this: I love your products. I'm a loyal customer. People are more forgiving than you think, speak up, admit you dropped the ball, and DO something about it in your next updates to Lion and whichever versions of Leopard you are still actively maintaining.
There's no shame in admitting when you're wrong. The shame is in hiding behind false promises and walls of silence.
--Loyal customer, but feeling rather betrayed by all this.

Answer 1

The old rule of thumb was to keep 10-12 GB free. Any lower than that and you will start to have trouble. I was very close to that for a long time and never had any complaints. Now, Lion "encourages" 20% free space (on my newer 250 GB drive) so I try to keep it with more than 50 GB free.
Do you still have the original memory in that machine too? The metal plate you have to remove in the battery compartment also provides access to the RAM. Your machine will take 2 GB of RAM, possibly 3. You definitely want to max that out too.
Regardless, you definitely need a new hard drive. When Apple switched to PC components, they had to take a quality hit. These 2.5" notebook hard drives are not very reliable. I'm surprised your hard drive hasn't died by now. I usually get a new hard drive with every major OS upgrade. A $ 50 investment every couple of years is no big deal.
Unfortunately, you (and I) suffer from being an early adopter in 2006. Those 32-bit machines only accept 2 GB RAM (maybe 3) and are only 32-bit so they can't be upgraded to Lion. Because of this limitation, you won't see as dramatic an improvement as you would with a 2007 machine. If you run more than a couple of applications, your hard drive is always going to have to be doing some VM work. My 2006 machine has even lost its bluetooth. I gave it to my brother. My very similar 2007 Macbook is still running great.
So, you must get a new hard drive because your old one is likely on death's door. If you don't have at least 2 GB - get it. If you can't afford a new machine, you might want to consider an SSD. That might help mitigate your RAM limitations. You can spend from $ 100 to $ 350 and get a dramatic speed improvement.