Hal's Hardware Haven
~~by Hal Cardona

RAM, RAM, I Need More RAM!

Note from Hal:

I'm kind of at a loss here because I’m not sure what level to write to. I can write something for newbies or I can write to experts or somewhere in between. I would like to ask you to help me out. If this is too hard or simple for you, please drop me an email at abcomputers@pcsleuth.com and let me know.

With memory prices where they are right now, I feel there is very little reason for any modern computer to have less than 128 MB (Mega-Bytes) of RAM (Random Access Memory).  I have noticed there are some misconceptions about memory. I will cover some of the common ones here first:

Common Misconceptions About Memory

• Hard Drive space versus RAM. 
  • Hard drive space, usually measured in Gigabytes or Megabytes is different than RAM.  Your hard drive is where you store information; think of it like a garage.  The bigger your hard drive (garage) the more information (stuff) and programs (cars) you can store.  RAM is more like your driveway, the more RAM you have the more things you can have loaded from the hard drive at one time.

• System Resources versus RAM. 
  • System Resources refer to some special (and limited) areas of memory that windows uses to store specific information (like icons).  When people run out of system resources, they often receive a message saying they don’t have enough memory to open an application.  Unfortunately adding RAM will not correct this type of error.  (I will write a column about System Resources and what can be done to correct this problem in a later column.)  Update from the editor:  Read Hal's article on System Resources here!

   

• Virtual Memory versus RAM. 
  • Virtual memory is an area of your hard drive that your operating system uses to simulate RAM.  When your system starts to run out of available RAM, you computer starts to write some of the information in RAM to virtual memory.   Unfortunately, since hard drives are so much slower than RAM, your system slows down when this happens.  If your computer seems to access the hard drive a lot (thrashes), then more RAM may help to minimize the use of virtual memory.

   

• Bits and Bytes.
  • Computers store and manipulate information as 1s and 0s, each one or zero is a bit, 8 bits is a Byte (note the capital B).  In computer terms a kilo is not 1000 but 1024 (the closest power of 2 to 1000, 20¹⁰) so a kilobit (kb) is 1024 bits and a kilobyte (KB) is 1024 Bytes or 8192 bits.  A Megabyte (MB) equals 1024 KB or 1048576 Bytes.

Why You May Need More RAM

Your computer may need or benefit from additional RAM if it spends a lot of time swapping things to and from virtual memory.  If you load a lot of programs when your computer starts, you are starting to use lots of your RAM.  If you work with large files, each file uses RAM.  Graphics manipulation programs (like Photoshop), video editing programs, (like Premier) and, of course, 3D Games, all use lots of RAM.  The more programs you have open at one time the more RAM you will need.  Probably the biggest consumer of RAM is your Operating System.  At this point the next version of Windows (XP) looks like it will require at least 128 MB of RAM and it prefers even more!  I will be writing a column on the hardware you need to run Windows XP as the release date approaches.  Right now I recommend 256 MB RAM for Windows XP.  

Types of RAM

There are several types of RAM.  For the sake of brevity and simplicity, I’m not going to cover all of the  types here, but will discuss the most common types used in Pentium Class and later PCs. As I discuss the various types, I am going to use some acronyms here that I won’t be defining.

• 72 Pin SIMMS were primarily used in 486 and early Pentium computers and some older Macs.  They come in several types including Registered, Parity, EDO , FPM and ECC.  In most systems, 72 pin SIMMS need to be installed in pairs.

• 168 Pin SDRAM is currently the most commonly used in both Macs and PCs.  It is available in PC66, PC100 and PC133 speeds.  The number after the PC refers to the speed at which the memory can function.

• SoDIMM RAM is used primarily in Laptops; it is available in various Pin configurations and types that roughly correspond with the other types of RAM listed.

• RAMBUS RDRAM is used only with Intel processors (Pentium III and Pentium IV). It is expensive in comparison to SDRAM and DDR SDRAM.  It is available in various speeds such as PC600, PC700 and PC800.

• 184 Pin DDR SDRAM is SDRAM that runs roughly twice as fast. It is also available in various speeds such as PC1600 and PC 2100.

Some RAM needs to be installed in matched pairs.  It is also a good idea not to mix types of RAM (i.e. don’t mix EDO with FPM RAM).  Most motherboards can use faster RAM with slower RAM, but the faster RAM will run at the speed of the slower RAM.  Check with your motherboard or computer manufacturer for details specific to your system.  

How To Buy RAM

Before you can go out and pick-up a few sticks of RAM for your PC, you need to identify the type of RAM that is required by your PC.  The best way to do this is to check your PC or motherboard's documentation.  If you need some help, the memory sellers Crucial Technologies and Kingston have wonderful websites that you can use to identify exactly the kind of RAM your PC requires. Their prices are fair and they sell high quality memory. You can also visit a local computer shop to purchase RAM and even have them install it for you.  

How To Install RAM

Before you install your new RAM, there are some precautions you should take:

• First shut down your PC and unplug the power cable from the back. 
• Make sure that you have either disconnected or powered off all your peripherals (printers, scanners, etc.). 
• Remove the cover from your PC. 
• Look inside and locate the RAM slots.  Make sure that you have unobstructed access to the slots.  You may need to remove some additional components to gain easy access. 

• Before you stick your hand inside or remove anything from inside the PC, you need to ground yourself so you don’t damage your new RAM or anything inside your PC.  To ground  yourself, either touch the power supply (the big silver box that the power cord plugs into) or use a grounding strap (about $5.00 US at Radio Shack).  If you choose to use the power supply method, you need to maintain contact with it while you are working inside your PC. 

Now you need to check the orientation of your RAM and slots. 

• Look carefully at the bottom edge of the RAM, you will see some notches. 
• Now look at the slots on your motherboard and you will see corresponding tabs inside the slots. 
• Align your new stick of RAM with the notches and install it according to the instructions from the motherboard or computer manufacturer.  With some types of RAM, you install it by pushing it into the slot; with other types you install it by gently tilting it into place.  RAM from Crucial comes with installation instructions.

Now just reassemble your PC. I leave the cover off at this point just in case something isn’t quite right.  Boot your PC and make sure that the BIOS recognizes the entire amount of RAM (watch the RAM count as your PC boots).  If everything is recognized, allow your PC to boot and check to make sure your Operating System  recognizes the new RAM.  In Windows 9.X or 2000 right click on My Computer and choose Properties and look at the General tab and you should see your new RAM.  If everything is functioning fine, then put the cover back on.

If your PC won’t boot or you experience a problem, make sure that your new RAM is correctly and completely inserted.  If the problem still persists check following:

• Make sure that you reassembled your PC correctly.
• Make sure that your new RAM is compatible with your PC.
• Try your old RAM without the new RAM, or the new RAM without the old RAM.  There may be a compatibility issue between the new and the old RAM.
• Try swapping the RAM slots.  Occasionally RAM will work only in specific slots on a motherboard.

Enjoy.

Hal Cardona, PC Sleuth, serves as tech support and/or offsite Sys Admin for over 200 clients around the US.  He designs, builds, and troubleshoots networks and builds custom computer systems.