Magoo's Wise Words
Guide to Buying a Computer

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Memory

Memory stores files and programs that you are using while the computer is on. It is one of the most important components of your computer, performance wise. The features you need to look for in memory are size, speed, and latency. Size and speed are the most important. Both can affect your computer's performance vastly.

Speed - First, we will tackle speed. You want the fastest memory you can buy. Memory is rated by the speed it can transfer data to the processor. For example, DDR 400 PC 3200 is memory that communicates with the motherboard at 400MHz and can move 3.2 MB/sec of information. The first number refers to the speed your memory communicates with your FSB. Remember that your memory won't go any faster than your motherboard can support, which is why its good to have a fast Front Side Bus on the motherboard. The second number is how fast your memory can move information through your system.

Size - The next feature of memory is size. How much memory you need depends on what types of applications you run. If you are just surfing the internet or typing documents, you could probably get by with 256 MB. If you are running games, video and picture editing, or multiple applications at once, then your system will run much smoother with 1GB of memory. For a general purpose computer running Windows XP, 512 MB is normally the minimum amount you should have. Windows Vista will require more.

The more memory you have, the less you computer will have to use your hard drive to store the files and applications you are working on. Since memory is much faster than your hard drive, this will increase the performance of your computer noticeably.

Latency or Timing - The last number you have to look at when shopping for memory is the latency or timing. This number has to do with how long your processor has to wait when requesting information from the memory. The lower the better. Older memory will report a number called CAS Latency. Normal CAS for economy memory is 3.0. Higher grade memory will have a latency of 2.5, and top end memory will have a latency as low as 2.0. New memory reports memory timing rather than latency. You can think of timing as the CAS Latency on each of several consecutive requests. Timing will for high grade memory will look like: 2-2-3-5-4. Budget memory will have higher timing and perform slower.

Power Supply

Power Supplies are fairly simple to pick out. The only feature that gets a lot of emphasis is the Wattage. This is how much power the power supply can produce at one time. A basic computer with a 2 GHz processor needs at least a 300W power supply. A faster processor or additional devices connected to the computer raise you power requirements. I would probably recommend at least 400W for a new 3.5 GHz processor.

Devices such as hard drives and CD/DVD burners are fairly power hungry and raise your power requirements. You should be able to find a power usage rating on each device in your computer, and add up the total of all the devices to find your power requirements. If you don't want to do the math, just get a power-supply that is slightly bigger than you think you need. You can't have a power supply that is too big. If your computer doesn't need the extra power, your power supply simply won't produce it.

Power supplies are usually in the range of $30 - $80. More expensive power supplies are built with better parts, but will not give you any performance advantage. The only thing that you need to watch out for is bargain basement power supplies. A power supply built too cheaply will not provide precise enough voltage and will cause random crashes and other problems. If the deal looks too good to be true, it probably is. You will not regret a quality power supply.

Next =>[Magoo's Guide to Computer Shopping- Page 7, CD and DVD Drives]