PART I – INTRO & FRAGMENTATION
Many people are under the impression that a computer’s performance deteriorates with age. I’d like to dispel that myth: computers are mostly solid-state technology that is largely unaffected by age. I’m not saying that older computers don’t run more slowly, but once we correct the notion that the slow-down is caused by its unalterable age, the problem becomes one that can usually be remedied without buying a newer computer.
First, let’s understand what doesn’t cause a computer to slow down:
Computer processors are digital electronic transistor-like switches, sealed in a hard plastic package; these are solid-state devices that either work or don’t. They may get fried if exposed to a power surge, but otherwise, they don’t slow down. Tablet Oscilloscope
Computer memory is comprised of similar components and works or doesn’t work, just the same.
A computer motherboard is nothing more than wire traces on a piece of plastic, usually with more solid-state devices plugged into it or soldered to it. Motherboards don’t slow down, either.
Computer power supplies are exposed to some of the most extreme conditions a computer experiences. That’s why they burn out more frequently than most other parts, but even they don’t cause performance reductions; they either work or they don’t.
So what does cause a computer to slow down with age?
The biggest culprit is data storage. Imagine trying to look for something in a file cabinet if it was the only item in the drawer; it would be pretty easy to find, right? If there were even just a few items in the drawer, it would still be simple to thumb through them to find the one you wanted. What if the drawer was completely filled? It might take a little longer, right? That’s what happens on a hard drive when you install an operating system, applications, and data on it. Every time you download more.mp3 songs, import more.jpg photos from your camera, or type up new word processing documents, you’re stuffing more things in the file cabinet which is your hard drive.
Unlike the processor or memory, the hard drive is usually not a solid-state device; it has moving parts. Consequently, the time it takes to read or write hard drive data is on the order of 1,000 times slower than solid-state devices like RAM or a USB thumb drive. Couple that with the fact that you keep adding more and more stuff to it, and you can begin to understand the problem.
In reality, it’s even worse than you imagine. When you save a document to the hard drive, it gets stored in a specific space on the drive. The computer tries to allocate hard drive space as efficiently as possible, so if more stuff gets written to the drive after that, it’s stored in the next-available sequential space. (For the hard-core techies reading this, yes, I know that this explanation severely oversimplifies the process.) Unfortunately, that means that when you next edit that initial document, there isn’t any contiguous space on the drive for the new data to be stored, so it ends up getting stored elsewhere, separated from the first part of the document. Later, when you try to read this document back into memory, it takes a little longer than it would for a contiguously-stored document because the computer must make a jump in the middle of reading it to find the rest of it. This is known as fragmentation. Another cause of fragmentation is when files are deleted, as that creates holes the computer tries to fill with subsequently-saved data, but the holes are almost never the right size for the new files being saved, so the newly-saved files also get broken up into noncontiguous pieces.
Don’t think your use is the only force causing fragmentation on your drive, either. Virtual memory, pointers to recent files, various cache files, and updates/patches use and release hard drive space all the time, causing fragmentation, even if you never intentionally save another file to your computer. Fortunately, fragmentation is relatively easy to cure. Microsoft Windows comes with a tool that does it for us – all we have to do is use this tool from time to time, and it rearranges the files on the disk to do its best to store them all contiguously. Lucky for us, a lot of the stuff we store on our hard drives doesn’t change all that frequently. Operating system files, installed applications, and even our music and photos rarely change in content or size, so once they get defragmented into less-dynamic areas of the hard drive, they should be fine.
PART II – DIGITAL HOARDING
After fragmentation, the next issue to discuss about how hard drives slow down our computers is the increasing volume of data being stored on them. If you’ve seen a phonograph turntable, you have a rough notion of how a hard drive operates, but imagine it spinning much faster. Instead of 33 or 45 revolutions per minute, hard drives operate at 5,400, 7,200, 10,000, or even 15,000 revolutions per minute. For even the slowest hard drive to spin around to the complete opposite side of the disk may take under 1/100th of a second, but like a phonograph turntable, rotation isn’t the only motion the drive makes; the head also moves in and out, radially, and that motion is significantly slower. When a hard drive has little data on it, that data is generally stored close to the center, so the head only needs to traverse a tiny fraction of the radius of the disk, but as more and more data get stored, more of the radius of the disk is used, so the portion of the radius that the head must travel gets longer, making data reads and writes slower.
Fortunately, this type of performance degradation can frequently be mitigated, too. People tend to be terrible pack-rats about what they store on their computers. Hard drives become like black holes, collecting years of data that may never be used, needed, or even seen again. If the computer was faster when it was new, before it had all this data on it, you may well be able to restore it to that level of performance if you could clean out some of this data. There are countless ways to identify and remove unneeded data from a hard drive. Windows comes with a few tools that may help:
Disk Cleanup searches for several categories of junk left on your drive and enables you to remove them.
Add/Remove Programs helps you find and remove old applications and Windows Components that you no longer use or need.
Even your own old documents, music, movies, and photos can be parsed and either deleted or moved to offline storage (such as burned to CDs/DVDs or uploaded to network or even Internet storage facilities).
In extreme situations, you can also reduce some of the cache sizes, such as the System Restore cache size or even the Recycle Bin. By default, these take up 12% and 10% of your hard drive, respectively, and unless you’re prone to deleting things you shouldn’t have, cutting these in half frees up 1/9 of your hard drive, immediately and without undue risk.
Professionals may also be able to help you identify more ways of freeing up space, such as disabling Offline Files if the feature isn’t needed, deleting old user profiles, removing old printers, reducing Internet cache settings, etc. Frequently, programs leave remnants of themselves behind on your hard drive, even after being uninstalled; these may also be deleted. Misconfigured virtual memory settings may also hog up more of your hard drive than is actually needed.