I get a lot of questions from people who are trying to decide what specific hardware to put into their computers. More often than not, they are trying to take a very old computer and make it usable again. The problem with very old computers trying to run current operating systems and applications is that it requires almost an entire new computer worth of upgrades to bring it up to speed. On the other hand, I've used several computers now that are a few years old and only need a very simple upgrade to keep them usable for another year or two. The problem is that most people simply don't know when it's worth it to upgrade and when it's time to just replace it all. Fortunately for them, we can answer most of the questions here.

Why do computers start fast but get slower over time?

When you first receive your computer, it only has the operating system (Windows, OSX or Linux), a few utilities (Dell, Lenovo, HP, etc) and a few applications installed. Over the course of a few years, you will create, copy and delete 100s of thousands of files. You will install loads of new applications and update existing ones. You will watch movies, surf the web for 1000s of hours, play games, send countless emails and more. So what's causing the slow down? The short answer is, lots of things.

Creating and deleting all of those files causes fragmentation. Unless you have a Solid State Drive (SSD), you should be defragmenting your hard drive every month or so. That will help a bit with general disk-read speed. If you have an SSD, DO NOT defragment your drive. SSD performance is not affected by fragmentation and they will actually wear out faster if defragmented regularly. If you're not sure if you have an SSD, just listen when loading an application. Does your computer make a clickety-click noise? If so, then you have a traditional hard drive. Also if your computer and hard drive are from 2008 or earlier, you probably don't have a SSD. As of the writing of this article (March, 2009), the vast majority of computers do not have SSDs.

Another major reason that computers slow down is because software actually gets slower over time. That's right - when you upgrade to version 2010 of whatever software it is, chances are that it will be slower than the 2009 version. Why is that? Shouldn't software be getting FASTER as more development time is put in to it? One would think so, but most software manufacturers simply want to add new features to their software, not speed them up. In fact, they are totally accepting of the fact that their new software will be slower and they rationalize it with the fact that this year's computers are twice as fast as those of two years ago. The only exceptions are web browsers. Those, including Firefox, Chrome and IE, have been making strives to increase performance with every new release. Cheers to them, but for you, you are out of luck. You can try turning off features and options in your applications to hopefully reduce the loading time. You can ask around online to see if there is any way to make them perform better. Chances are that they will be as slow as they are and that's about it.

One of the biggest culprits though for slow-down happens gradually and incriminates almost every major software manufacturer to-date. Most slow computers have lots of applications with services that run all the time. Is your computer's blood pumping slow enough to give an android a stroke, but you insist that you haven't installed all of these things? Most people don't have any idea this is going on. What has happened in recent years is that many software applications have taken to adding a service for your convenience that "checks in" with the company's server to see if there is a new version of the software available. This isn't bad in itself but when you have 20 applications that do it and their updater takes up 10MB of RAM, all of a sudden you are using 200MB of RAM just for the ability to be notified if some application you have installed has a new update that you will be nagged to death to download! That's not the worst of it, though. See, software has not only become slower but it has also become much bigger. What's did the software companies do to solve that? They loaded as much of that application into memory as possible when the computer boots up. This can make it take 5-10 minutes to boot and consume 250MB more memory. What those "quick" launchers do is pre-load the application into memory so that when you actually go to launch it, it appears to launch very quickly. They've simply moved the slow part to when your computer boots and also have removed some usable memory from you.

Many of these applications have settings where you can turn off the "system tray icon." You can also look for words like "Enable quick launch" and "Start when windows boots." Turn all of those off unless you are sure that you run that application all of the time. For example, if you look at PDFs daily, you would want that feature enabled for Adobe Acrobat. For most things, you can turn that off. You can also usually shut off those automatic checks for updates.

The other biggest culprit is caused by users who are simply trying to be very safe online. Users who have more than one anti-virus or anti-spyware product installed are basically making the computer crawl on its knees. Those products usually read and process every single byte of every single file written-to and read-from the hard drive live. That prevents the system from running malicious code but it also is very, very slow. You only need 1 anti-virus product and should consider running anti-spyware scans weekly but not necessarily live. Just make sure that your anti-virus product keeps its definitions up-to-date and you should be golden.

All of these problems can make it feel like the digital pipes inside your machine are filled with digital cholesterol. Stay on top of what is being launched on start-up and what is running constantly on your machine and you will be able to keep those pipes mostly clean. If you've done this but your computer is still not running the way you'd like, then you can adopt a phrase we use in the industry. "Throw some hardware at the problem."

What is memory?

Your average Joe tends to get a little confused about "memory" in computers. If you know what it means then skip over this part. If not, then I will try to explain.

Modern computers have two types of things that people call "memory." One is RAM and the other is hard disk space. When people say "I'm out of memory," they could mean either. I assume if the person is technical that "out of memory" means they don't have enough RAM to accomplish a certain task. I assume if they are not technical that they have run out of storage space, possibly because they have filled the computer with movies, music or photos.

The correct usage is to refer to RAM as memory and storage (where you install applications, and put movies, music and photos) as storage or hard disk space. From this point on I will use those terms accordingly.

Common bottlenecks in PCs

If your computer is running slowly, first read the section up top about why that may be. If you believe you have resolved as many of those issues as possible and you are sure that your computer is running slowly because the games and applications you now want to run are too demanding for it, then let's look at the options.

If, as of today (March 17, 2009), you have 512MB or less of RAM and are trying to run the latest software and OS, I would say that would be a major issue. It may not be your only major issue but generally a $25 upgrade will get you to 1GB and your computer will usually run a little better. Modern applications like Firefox and Word easily use 150-300MB while running and having less than 1GB today just isn't enough.

If things just take a long time to load (from click to on-screen), the problem may be a slow hard drive. I'm not going to get into solid state disks in this article much so I'll stick to regular magnetic hard disks. Systems with older 5400RPM hard disks are going to have significantly slower loading times than ones with newer 7200RPM and 10,000RPM (10k) drives. 10k drives are the ultra-high performance ones and may be overkill. A 500GB or 1TB (1000GB) drive running at 7200RPM should provide a huge boost for an older PC. You will probably end up with much more storage space to boot.

If you are having problems playing the latest games and you have turned all of the settings down as much as possible, you may want to consider trying a faster video card. Computers have dedicated processors for handling just 3D graphics and these are upgradable, so long as you have the right connector inside your computer. The old kind is AGP and the new kind is PCI-Express or PCI-X. If your computer has AGP, you are mostly out of luck. Consider replacing everything. If you have PCI-X, you can put in a new video card for around $150 that will work well. Don't bother with the $400-600 ones because your CPU and other parts probably won't be able to fully utilize it. There will be bottlenecks elsewhere.

Since your graphics port sits on your motherboard which is inside your computer, you can find out what type it is (AGP or PCI-Express/X) by looking up your particular model of computer or motherboard. If you're not sure what motherboard you have, you can open up your computer and have a look inside. Once you find a manufacturer written on it (there are too many to list here) you can search for a model # and find out the details on their site. If your computer is made by a major manufacturer such as Dell, HP or Lenovo, you can usually find out with the service tag on the computer. If you have a laptop, you are most likely out of luck because the video chip is one of the things that is non-upgradable 99% of the time.

If you have a desktop PC and you didn't buy the absolute top-of-the-line processor when you got it, chances are that you can put in a faster CPU. This is especially true of AMD Athlon 64, AMD Phenom and Intel Core 2 processors. Most of the time, if the socket fits and you have the latest BIOS, you can install a faster CPU. Figuring out socket-types and compatible processors is beyond the scope of this article. Make sure to find out which motherboard you have and what it supports before buying anything. What you will get is faster processing times for video, music and photo editing as well as smoother running applications.

If your only issue is that your screen isn't big enough, then just buy a bigger monitor. Almost any PC can take almost any monitor. The same goes for keyboards and mice. They are mostly interchangeable.

The upgrade cut-off

Sometimes it just doesn't make sense to upgrade because no matter what you do, the system just can't improve in performance. Generally after about 3 to 4 years, depending on how expandable the computer was when you got it, you are at the cut-off point. Consider the following list:

Don't bother upgrading if:

You want a really fast gaming machine and you don't have PCI-Express.
You want great performance with the latest apps and you have a Pentium III, IV, Celeron, Athlon or Athlon XP
You are planning on getting a new system within 6 months anyway.

Always try for the upgrade if all you need is:

More storage space for videos, music or photos
A better monitor, mouse or keyboard
Wireless capabilities

Helpful Resources:

This utility (cpuid) will tell you all about your processor and RAM.
Windows Process Explorer is invaluable for tracking down pesky processes that are slowing down your system.
Tom's Hardware has many charts and benchmarks with performance comparisons