What is RAM Memory?
Consider the desk-and-file-cabinet metaphor for a moment. Imagine what it would be like if every time you wanted to look at a document or folder you had to retrieve it from the file drawer. It would slow you down tremendously, not to mention drive you crazy. With adequate desk space - our metaphor for memory - you can lay out the documents in use and retrieve information from them immediately, often with just a glance. Here's another important difference between memory and storage: the information stored on a hard disk remains intact even when the computer is turned off. However, any data held in memory is lost when the computer is turned off. In our desk space metaphor, it's as though any files left on the desk at closing time will be thrown away.
If you're running Windows 9x or higher and have less than 64 megs of RAM, go out and buy more. I hate to say it, but it's the truth.
Don't Mix and Match
It's important not to mix different types of memory modules in your PC. Most PCs have three DIMM sockets on their motherboards, and one or two of them are usually free. Adding RAM is as simple as plugging in new DIMMs.
DIMM of the Day
RAM is sold in the form of chips contained on small circuit boards called memory modules. If your current desktop PC was manufactured in the last three or four years, it most likely uses 168-pin DIMMs (dual in-line memory modules). DIMMs vary depending on their capacity (16MByte, 32MByte, 64MByte, and 128MByte), the PC's bus speed, the type of RAM chips they contain, and other factors. You can usually determine what type of DIMM your PC uses by consulting the PC's manual or by calling the manufacturer's technical support line.
SIMMS Like Old Times
If your PC is more than three or four years old, it probably uses SIMMs (single in-line memory modules). Though the examples of memory modules shown in the accompanying photos are DIMMs, the process of upgrading SIMMs is similar. The differences are that SIMMs pivot rather than plug into their slots, and they must be installed in pairs. Most PCs today require a type of memory called PC-100 (100MHz) SDRAM, though slightly older systems need PC-66 (66MHz SDRAM), and somewhat newer systems depend on PC-133 (133MHz VC SDRAM). Some brand-new high-performance systems use a new type of memory known as RDRAM (Rambus DRAM), which currently costs considerably more than DIMMs. Another new type of memory, known as DDR (double data rate) SDRAM, is showing up in some high-speed PCs, mainly those that use AMD processors. To find out more, check out www.rambus.com or www.ami2.org.
Blue screens during the install procedure of Windows 2000 or XP. This is one of the surest signs of faulty memory.
Random crashes or blue screens during the running of 2000 or XP is another sign of faulty memory. Note that heat can also be a culprit in the case of general flakiness like this, so you should test for that possibility too.
Crashes during memory intensive operations. 3D games, benchmarks, compiling, Photoshop, etc.
Distorted graphics on screen. This can also be related to the video card.
Failure to boot. This can be accompanied by repeated long beeps, which is the accepted BIOS beep code for a memory problem. In this circumstance, you cannot test the memory with diagnostic software, so your only option is testing by replacement, either at home or at your computer dealer.