MisterMe said:
Mikuro,
Takeaway message: If you are experiencing a slowdown on Windows, file defragmentation is one of the first things that you try. If you are experiencing a slowdown on a Mac, file defragmentation is among the very least of your concerns.
I won't disagree with what you've said, but I'm not harping about a mythical problem just because it's frequently called a problem! My own personal experience has shown very noticeable effects of fragmentation. I consider it something that's definitely worth keeping in mind.
Part of the reason is because I do a fair amount of video work. Large files that go in and out frequently build up fragmentation in a hurry. For a time, my boot partition had very, very little free space. Not enough for VM. But even after deleting a ton of stuff, the free space on my boot partition was still fragmented. That meant that all new VM files had to be fragmented. NOT GOOD. I could hear my disk thrashing about all the time as I switched apps. It killed performance like nothing else. Defragmenting solved this problem.
These days, I rarely defragment my boot partition, because I excercise sufficient caution in the way I use it. I never use my boot partition for video anymore. I try to keep it as static as possible, using other partitions for things that go in and out a lot. This cuts down on 90+% of the problem of fragmentation. That's enough so that I don't worry about it anymore.
However, I still defragment my other partitions about once every month or two. I really need to. If I don't, it will get to the point where I can't even play videos at full speed, because the fragmentation makes it impossible for the file to be read fast enough. Ugh.
I've never seen anything hurt performance anywhere near as much as file fragmentation. This is coming from someone who's been using Macs exclusively since System 7. Actually, fragmentation was a smaller problem before OS X, since you could just turn of VM, and even if you did have it on, it wasn't dynamic, so it wasn't at risk of being fragmented (unless you turned it on when your disk was
already fragmented). A big reason fragmentation is such a problem in Windows is because it handles VM relatively poorly.
And of course, the problem of VM fragmentation sharply decreases as you add more RAM to your system. When I only had 256MB, disk speed was my top concern. With 1GB, it's not nearly as big a deal.
The bottom line is, you shouldn't generalize. The effects of fragmentation vary greatly based on the setup of the machine (hardware and software), the habits of the user, and the kind of work being done. Your setup and work habits clearly don't promote the problem, but mine and many others' do, and it takes a good deal of conscious effort to keep the problem at bay. All we know about the last user of the system is that he was a graphic designer. Graphic design really DOES promote the problem, so even with 70+GB of free space, it is quite possible that there is horrible fragmentation. And with 512MB of RAM, which is only the practical minimum these days, that could cause serious a performance hit.
Again, more details about when and where the slowdown occurs are needed to properly diagnose it.
Edit: I see some other people posted while I was typing. Modern defragmenting programs are smart about the hotband, so that's not really an issue anymore. I actually don't user defragmenters, though (they have not earned my confidence). I just back up, reinitialize, and restore. This does not respect the hotband, but even so, it offers a definite improvement. For some people it might create a slight short-term performance hit. For others it will offer a huge long-term gain. Again, it depends greatly on habits and setup, so generalizing is bad. ShowVolumeFragmentation is a very useful tool for determining if defragmenting is worthwhile.
