We continue this week's column by defining some computing terms.

RAM stands for "Random Access Memory." Your computer uses RAM as a temporary workspace. The CPU transfers data and applications from long term storage devices (hard drive and optical drive) into RAM, then runs the programmes and accesses data from memory. New data is created within your system memory before it's ever saved to a storage device. Every byte of information used by a PC during its operation flows through RAM.

Access to data in RAM is immediate: The CPU can read or write to any location in memory without having to muddle through the adjoining data.

Most RAM used in PCs today is dynamic RAM, or DRAM. It's called "dynamic" because the memory chips must receive new electrical charges (a process known as memory refreshing) thousands of times a second, or data stored in the chips is lost. This is why information saved only in RAM is lost as soon as your PC is turned off or restarted.

RAM AND PAGING FILES

If a program or data file is too large to completely reside in RAM, PCs use dedicated areas of the hard disk to store the overflow. This dedicated disk space is known as "virtual memory." The paging file (swapfile) in Windows is an example of virtual memory. Windows uses the paging file as a holding tank for information being transferred in and out of your system RAM. The less RAM you have, the more frequently your paging file is used.

Although a paging file enables a system with a relatively small amount of memory to work with files that exceed the amount of available physical memory, using the paging file instead of physical memory has a huge negative impact on performance. Hard drives move data in order of magnitude slower than even the slowest RAM.

This means that the more memory you add to your system, the greater the number of programs you can run, and your system can work with larger files before resorting to the paging file. In an ideal situation, the paging file would never be used. In practical terms, you want to install enough memory to handle the largest amount of work (or play) your PC performs on a routine basis.

WHAT ABOUT DDR3?

DDR2 (double data-rate 2) is the standard memory for all Intel and AMD desktop computer systems today. However, we are now seeing an expanded push for DDR3 RAM and this push should increase in 2009. The new memory 'spec' promises higher bandwidth but at the cost of higher latencies. In Late 2007, this compromise along with its higher prices made DDR3 seem pretty irrelevant.

But we have seen one promise from DDR3, which is really high clock speeds. DDR3 modules are already pushing 1,800MHz whereas DDR2 topped out at 1,066MHz. As clock speeds increase, the latency becomes less of an issue. Combined with the higher front-side bus speeds of Intel's 45nm Penryan CPU, we think DDR3 is starting to show some promise. With that said though, for now, you can't lose with DDR2 and it's comparatively cheap, too.

Column done by Explorers Computer Sales & Service Limited, 34-36 Old Hope Road, Kingston 5

Tel: 908-2945, Fax: 754-0920,

Email: sales@explorerscomputerjm.com

- Technical Writer Kamar McIntyre