Tips: How big should your RAM capacity be?

Some things have changed drastically, some have remained the same, but the general architecture of a computer, for example, is not actually too different today from what it was when the first digital computer was built.

A computer still comprises a processor, input and output devices, a storage device such as the hard disk and the floppy diskette, and the memory. The memory is called RAM (Random Access Memory) because data is stored and accessed in a random way to ensure the highest possible speed.

Even a Personal Data Assistant (PDA) requires RAM. RAM is volatile, which means that the content -- all the data stored in it -- will be lost the moment the power is cut. Do you still wonder why your work is lost each time you have a blackout while composing your letter? It happens because the computer has not saved a copy of the data in RAM on the hard disk, which serves as the computer's non-volatile data storage device.

Today, the RAM -- more commonly known today as DRAM (Dynamic RAM) -- is actually a separate component consisting of one or more banks of memory chips. There have been major advancements in the way the DRAM module works, and all purport to be faster. The faster the RAM, the better the computer's overall performance.

There was a point when processors actually became too fast for the memory, and a wait state was added to avoid overflowing the memory with data. Today, several technologies have made the wait state unnecessary.

Then there are the related terms that one perhaps has to be at least somewhat familiar with. These include the SIMM and DIMM. The SIMM is older than the DIMM, and supposedly slower, too. What about the notebook computer? The DIMM for the notebook has to be designed differently due to the small amount of space available. Thus, for the notebook, we use SODIMM (Small Outline DIMM).

How big should your RAM capacity be? This is a common question each time Microsoft introduces a new operating system. The joke is that, at one point, Bill Gates said that 64 KiloBytes should be enough for a personal computer. That was when DOS was the pervasive operating system on the PCs. Today, however, 256 MegaBytes, or four thousand times larger, seems to be the minimum for Windows XP.

One thing to note is that, up to a certain point, the more memory we have, the speedier the computer. That point is usually called "the sweet spot". Beyond that point, we have diminishing returns. If we do not have enough memory, the computer has to store the data temporarily on the slower hard disk.

In the past, some memory modules were not so reliable. If our system had four modules and one of them was defective, the system would not boot. Or, we would have intermittent problems, which sometimes could be fixed, temporarily, by taking out the modules and messaging all the chips to press it again to the board. Today, memory fabrication is much better, and we seldom encounter defective memory modules.

Why is important to understand all these types of memory? We need to know them because different computers may use different types of RAM modules. If you want to increase your memory capacity, you will have to buy the modules that exactly match the specification of your motherboard. These modules even differ in the number of pins that connect them to the motherboard through the slots. We have 72-pin, 168-pin, 184-pin or 200-pin modules, just to mention a few.

The latest computers today use DRAM based on Rambus technology, and it is called RDRAM. Then there is also a specification called Double-Data Rate, which is abbreviated as DDR. And the latest toy in the store is the Dual Channel memory, which requires the latest motherboard, too.

PC enthusiasts like to play around with the RAM modules. They do not mind spending a fortune on RAM, and RAM makers know it. Corsair, for example, has the Pro Series XMS line of memory that has flickering LEDs, which adds a light show inside the computer casing.

If you decide to increase your RAM capacity, you really have to make sure you know what your computer needs. The best thing to do is to just take your PC or notebook to your favorite computer store and ask them to choose the memory modules for you. That way, you will immediately know if the modules are compatible or not. -- Zatni Arbi