Buying a new computer 101

Don't be seduced by fancy speakers, shiny cases or glowing parts

So you're on the market for a new laptop or PC. But how to make sense of the flood of tech abbreviations and jargon and buy the computer that's right for you? Here's a breakdown of the three most important parts of any computer.

1. Processor

Basically a computer has a central processing unit (CPU) and this is what does all the number crunching. A processor's speed is measured in megahertz (MHz) or gigahertz (GHz). The higher the number generally the faster it is. To give you an idea of the speeds we're talking about, 1,000 Mhz = one Ghz, which is one million cycles a second.

Processors are often divided into cores (like cylinders in an engine). Cores share the processing of running applications, so the more cores in a processor, the better it will operate. The newer the processor, the more efficient it is. Usually processors are made 10% more efficient every year. So a 2.4Ghz modern processor would beat a 3.2ghz processor from four years ago. Newer processors also use less power, so wherever possible, get a new processor (especially if you're buying a laptop).

2. Memory

The next critical part of any computer is the memory, often abbreviated to RAM which stands for Random Access Memory. Imagine memory as a massive blank spreadsheet. A computer with 16GB of memory is like a spreadsheet with 125,000 columns and 125,000 rows. Imagine writing all of your thoughts into all of that space. Memory reads and writes are scheduled and controlled by the processor. Every second your computer is writing thousands of things to and from memory. All of your running programs have to share the memory and it often takes time for data to read and write to the memory. Therefore, choosing memory that's faster will pay off in performance. Memory often comes in 1000Mhz, 1333Mhz, 1600Mhz speeds. Memory is cheap, so get as much of it as you can afford.

3. Hard Drive

The third most important part of any computer is the storage device, known as the hard drive. This is the place where files are saved when the computer is switched off. Older spinning hard drives contain magnetic platters with a metal arm that hovers above the metal surface reading and writing data. Spinning drives can only read and write to areas directly under the read head. Spinning drives can crash if dropped or moved violently.

Newer solid state drives are up to 20 times faster than spinning magnetic drives, but have smaller capacities and are more expensive. Solid state drives have limited write capacity. If you're too stingy and fill up your solid state drive too quickly the remaining free blocks rapidly wear out and the drive dies prematurely. The best systems have a mix of both cheap spinning storage for infrequently-accessed data and a faster solid state drive for Windows, programs and games to load from.

* * * * *

Other less critical parts of a computer include the screen, video cards, sound cards, power supplies, optical drives, wireless etc. If you are into games or video production then you'll want a faster, dedicated graphics card but most modern processors come with built-in average video cards that will do a good job.

Choosing the right processor, memory and hard drive is critical. If you spend more money on each of these three areas your computer will be more future proof. Don't be seduced by fancy speakers, shiny cases or glowing parts.

Generally, unless an advertised PC has a detailed specifications breakdown it has something to hide. PC/laptop margins are razor thin and many systems are stuffed with 4-year-old technology in some of the components. Older parts are dead cheap and vendors use these parts in bargain systems (or should that be not so bargain?).

Good Luck.

Helpful Processor Comparison Links:

Common Processor Benchmarks

Processor Power v Performance Comparison (higher is better)

As mentioned in Where do tech geeks get their tech support from don't be afraid to ask some geeks.