What’s not to like about a memory upgrade? As I discuss in the previous article, the dinero required for extra random access memory (RAM) is a mere pittance compared with a new CPU (or CPU and motherboard combination). Plus, RAM is easy to install, requiring only that you remove your PC’s case and plug in the modules. Your PC should recognize additional RAM immediately, with no silly drivers required. Also, additional RAM will make everything run faster in Windows . . . both the applications that you run and the operating system itself. Maybe you’re saying, “But there’s got to be a hitch somewhere.” True: The problem is that you have so many different types of RAM modules to choose from. Therefore, read through this article before you buy your RAM modules and keep these pages handy when you upgrade.

Figuring Out What Type of Memory You Need

To begin a primer on memory, review the different types of RAM available for PCs made within the last five years or so. One tip before I begin: If you’re considering installing a new motherboard and CPU on an older PC, you might want to double-check to make sure that the new motherboard will still use the same RAM type and speed as your current motherboard. (To check, visit the manufacturer’s Web sites to compare the specifications for your existing motherboard and the new toy, or you can refer to the documentation for both motherboards.) If not, the RAM that you add now won’t do you any good when you upgrade your motherboard. If you have your eye on a significant motherboard/CPU swap in the near future, I definitely recommend that you upgrade the motherboard, CPU, and RAM all at the same time. For example, the memory modules that work with your older Pentium III PC aren’t likely to work with a fast Pentium 4 motherboard. In cases like this, I recommend simply ordering a populated motherboard, which comes complete with a preinstalled CPU and the amount of RAM that you specify. The different types of RAM commonly used on PCs are

-  Rambus dynamic random access memory (RDRAM): These modules are very expensive, but they’re the fastest memory modules available on the market today, with access speeds up to 1200 MHz at the time of this writing. If your PC uses RDRAM, it’s really cooking already, so you probably won’t be upgrading for a speed increase anytime soon. (More likely, you’re preparing to add more memory to your existing RDRAM motherboard.)

-  Double Data Rate (DDR): These modules are the fastest standard 168- pin Dual Inline Memory Module (DIMM) available; they’re commonly used on today’s Pentium 4 and Athlon computers that run Windows XP. The double in the DDR name is significant because a DDR module effectively doubles the speed of the module (compared with older synchronous DRAM [SDRAM] memory). Also, DDR memory is assigned a speed rating as part of the name, so it’s commonly listed as DDR266 or PC2100 (for the 133 MHz speed versions) and DDR333 or PC2700 (for the 166 MHz version). As you might guess, the faster the access speed, the better the performance. The speed rating that you should choose is determined by the memory speeds that your motherboard supports. DDR memory modules have one notch on the connector and two notches on each side of the module.

-  SDRAM (sometimes called SyncDRAM): These modules take the form of standard 168-pin DIMMs. These modules are standard equipment for most Pentium III and some older Pentium 4 machines. SyncDRAM runs at an access speed of 133 MHz, and it’s the most common memory type used for PCs these days. SDRAM memory modules have two notches in the bottom and only one notch on each side.

-  Extended Data Output (EDO): These modules take the form of 72-pin Single Inline Memory Modules (SIMMs), and they are used in older Pentium motherboards. Typically, you must add SIMM memory in pairs. If you’re planning on adding memory to a motherboard that uses EDO modules, I strongly urge you to instead upgrade the Big Three motherboard, CPU, and memory. (I don’t intend to offend, but I’ll be blunt: Your PC is so far behind the performance of today’s models that it just isn’t worth adding EDO memory to your older motherboard. Plus, EDO memory is now much harder to find and is actually getting more expensive over time. Just chalk that up to the price of running antique hardware.) Here are two methods to determine what type of memory modules your current motherboard requires and what memory speeds it can handle:

-  Check the specifications: Refer to the motherboard manual. Or, if you purchased your PC from a manufacturer, check the documentation that accompanied the computer. If you didn’t get any manuals with a used PC, visit the company’s Web site for memory compatibility information or specifications. This is definitely the preferred method because you won’t have to open your PC’s case until you’re ready to install the new RAM modules.

-  Check the existing modules: If you can’t find any documentation, specifications, or data on the Web concerning your PC’s RAM modules, it’s time to remove the case from your computer. (For more details on removing the cover, see the step-by-step procedure at the end of this article.) Look for the memory slots on your motherboard; (Note: You might have more than one module already installed on your PC.) Your RAM modules might have a descriptive label (which will allow you to read the specifics without actually taking anything out); however, it’s more likely that you’ll have to remove one and take it to your local computer shop. Use the instructions later in this article to remove a module; then protect the module in an empty CD-ROM jewel case when you take it for identification. The good techs should be able to tell you what type and speed of memory you’re using when presented with the module.

Deciding How Much RAM Is Enough

Every motherboard has a maximum amount of memory that it can support. You can install the maximum amount by filling up all the motherboard’s memory banks (sockets) with modules of the right type. Whenever possible, buy RAM modules of the same brand, at the same time, and from the same dealer. This will ensure that you are spared any compatibility problems when you install the modules. (Theoretically, any RAM module of the same type and speed should work with any other brand of RAM, but I date back to the earlier days of PCs when using memory chips from different manufacturers would result in errors and a locked computer.) In fact, I still hear tales of compatibility problems, even in our new, improved, fresher-smelling world. However, not everyone can afford to take a PC’s memory to the max even with today’s prices, buying a gigabyte of RAM modules can set you back. Therefore, the following table illustrates my recommendations for the minimum amount of RAM that you’ll need to run the different versions of the Windows operating system comfortably on your PC. (By comfortably, I mean my opinion of decent performance, perhaps with a copy of Microsoft Word running. Of course, memory-hungry applications such as Adobe Photoshop will only run their best with plenty of memory elbow room to spare, so I’d consider this the bare minimum.) You might notice that my recommendations sometimes don’t jibe with Brother Bill’s that’s because the folks in Redmond literally mean the least you can get away with when mentioning minimum memory requirements. With 24MB of RAM, Windows 98 is slower to awaken than my kids on a school day. Personally, I actually like to use my computer and not wait half an hour for a scanned image to load.

Installing Extra RAM

Ready to install your new RAM upgrade? Follow these steps to install a typical SDRAM or DDR module:

1. Cover your work surface with several sheets of newspaper (to protect your case).

2. Unplug your PC and place it on top of the newspaper.

3. Remove the PC’s case. Most PC cases are held on with two or three screws; just remove the screws and slide the case off. (Don’t forget to stash those screws in a safe place.) Other cases are hinged, often with a lock. If you’re unsure how to remove your PC’s case, check the manual that accompanied your computer.

4. Touch the metal chassis of your case to dissipate any static electricity on your body. An electrical charge can send your new RAM modules to Frisco . . . permanently.

5. Locate the DIMM slots. Check the motherboard manual, which should have a schematic that will help you locate the slots. Typically, the RAM modules are found close to the CPU, in the center or one corner of the motherboard.

6. Turn your PC’s chassis so that the DIMM slots are facing you  and make sure that the two levers on the side of the socket are extended. Note that the notches cut into the connectors on the bottom of the memory module match the spacers in the sockets themselves, so you can’t install your modules the wrong way. (Smart thinking there.)

7. Align the connector on the bottom of the module with the socket and push down with a light pressure to seat the module.

8. While you push down, the two levers at each side of the socket should move toward the center. After you correctly install the module, the two levers should be tightly flush against the sides of the memory module to hold it securely.

9. Slide the cover back on your PC and secure it.

10.Move your PC back to its place of honor and plug it in. 11.Restart your computer and prepare to enjoy a faster PC!