Does filling up internal hard drive slow down the computer?

HI,

*"does filling up my internal HD lead to a slower working computer?"*

Absolutely.

*"Or is there no difference compared to putting everything on a Lacie drive?"*

If you copy files over to the an external drive you can then delete the original files on your startup disk, hence freeing up drive space.

Control or right click the MacintoshHD icon on your Desktop. Click "Get Info". Under the General tab you will see Capacity and Available. Make sure there is at least 10% available disk space, 15% is better.






Carolyn 🙂

As your write to the disk, the more disk space you use, the slower the startup disk responds to commands. As I said before, never allow the free disk space to fall below 10 to 15% of the total drive.

"threshold"

*Control or right click the MacintoshHD icon on your Desktop. Click "Get Info". Under the General tab you will see Capacity and Available. Make sure there is at least 10% available disk space, 15% is better.*



RAM helps keep apps from crashing and freezing. If the hard disk hasn't enough free disk space, RAM can't help that.







Carolyn 🙂

Message was edited by: Carolyn Samit

alamosound wrote:
Is this a gradual thing: the more you jam onto your drive, the slower it gets... or do computers generally behave slower once you pass a certain critical threshold?

Also, does adding RAM counteract this tendency of slowing down?

Thresholds, slowdowns, & RAM are interrelated:

A Mac running OS X needs *scratch space* on a drive for temporary files & virtual memory. Virtual memory works by swapping chunks of data between RAM & the drive, allowing the much greater capacity of the drive for data storage to substitute for the limited amount of RAM in the Mac. The swap process is very slow compared to using real RAM, but as long as it doesn't occur too frequently, it doesn't really slow things down very much.

However, when the OS runs out of scratch space, it doesn't just slow down, it can become very unstable & even crash. Because this threshold is variable & hard to predict accurately, the frequently recommended 10-15% free space rule of thumb all but guarantees this will never happen.

There is also a gradual slowdown in drive performance as it fills up. Basically, this is because the drive has to retrieve data from increasingly more widely separated areas of the drive, so it spends proportionately more time moving to different areas than reading from them. However, OS X has some built-in mechanisms that partially compensate for this. Also, the drives in most Macs are very fast at moving from one area to another & include internal mechanisms to reduce the need to do this. Because of this, this gradual slowdown is small & except for some specialized applications, it is not much of a practical concern in day-to-day use.

So really, if your concern is keeping the Mac from slowing down, the most effective thing you can do is to load it up with as much RAM as you can afford & it can use. Beyond that, make sure you leave at least 10 to 15% of your startup drive free by offloading files to other drives or discs as needed.

Mac OS X does not require defragmenting.

There actually is an automatic defragmentation routine already built into the OS for files 2 MB or smaller. Since highly fragmented smaller files are the ones most affected (in terms of percentage of the time spent seeking vs. reading) by fragmentation, this is enough to mitigate the worst effects of file fragmentation quite well. There is also a "hot files" system that groups frequently used files together in the fastest part of the drive.

Just as relevant, the idea that files are read sequentially in their entirety one at a time in modern OS's is overly simplistic. In reality, intelligent buffering schemes in the drive itself & the multitasking, multithreaded nature of the OS complicate things quite a bit, with the result that artificial benchmarks show substantially greater benefits to defragmenting drives than can be realized in typical real-world conditions.

You also have to consider that the defragmentation process itself uses substantial resources (both in the OS & in the drive), especially for defragmenting large files. It would make no sense to slow down the computer to do this unless the net time saved is greater than the penalty imposed by working with files that remain fragmented. Some users that compulsively use third party defragmentation software frequently actually lose more time doing this than they could possibly save if they just let the OS handle it.

Yet another consideration is that a thorough defragmentation works the drive much harder than does normal use. Subjecting a high quality drive to the extra wear & tear of the process may not cause it to fail prematurely but it certainly doesn't do anything to extend its life!

With few exceptions, the only people that need to do comprehensive defragmentation are those that run applications that demand peak drive performance, like editing multiple HD video streams in real time. For these applications there are usually better, faster techniques, like partitioning multiple drives to handle the load & just erasing working partitions as needed to clear them of any fragmentation.

Gee. If I'd just read Jay Bullock's linked article first, I could have reduced my long post to one sentence from it:

"Optimizing them can be a major effort for very little practical gain."

🙂

Did you actually red the article you linked to? It does not state that Mac OSX does not require defragmenting. It does state however that:

"If your disks are almost full, and you often modify or create large files (such as editing video), there's a chance the disks could be fragmented. In this case, you might benefit from defragmentation, which can be performed with some third-party disk utilities. "

Defrag no needed on a Mac. Read here. http://support.apple.com/kb/HT1375






Carolyn 🙂

Hi alamosound;

One other fact that everyone has overlooked is that when you run the free disk space low, you greatly increase the chances for file corruption. This is especially true of the files the system uses for it's directory where it keeps track of all the other files on the disk. If this file corruption is corrected it can lead to all kind of strange problems in the future. Just one more reason not run the free disk space too low.

Allan

Yeah, but if your hard drive is so full it risks corruption and doesn't easily handle the large files you're planning to work with, then you have bigger problems than just fragmentation.

The Apple article states that the conditions for which defragmenting the hard drive has any +practical benefits+ are rare.

The Apple article states that the conditions for which defragmenting the hard drive has any practical benefits are rare.

Your right, but it doesn't say that it doesn't ever require it, As any on who's ever tried to set up Boot Camp on a fragmented drive would agree.