This is quite a long document. If you haven't much time, or can't be bothered with all the nuts and bolts of computer design, why not go straight to the summary?

Contents

• Introduction
• Desktop or laptop?
• Or maybe a netbook?
• What processor?
• Memory
• Hard drives
• Motherboard
• Graphics card
• Operating system
• DVD drive
• Summary
• Conclusion

Introduction

Buying a PC is a minefield. There are a huge array of specifications to consider, the CPU, the memory, the hard drive, motherboard and many others. The exact same specifications can be on sale for a range of prices - in much the same way as you can buy a box of ASDA Corn Flakes or a box of Kellogg's. The reason? Branding and quality.

To find your way around, here's a guide on what you should look for in a PC.

Desktop or Laptop?

Laptops are very popular these days. They offer a great deal of flexibility, and with the growth of wireless networks and 3G phone connections, they allow you to surf the net almost anywhere. The trade-off is that every time you buy a laptop, you also (of course) end up buying a new screen, which increases the cost. Components are also more difficult to source for a laptop, due to the smaller size, and that increases the price further.

£300-350 may buy you a budget laptop - but bear in mind that for the same price you could buy a desktop PC with a better specification. Remember also that laptops are prone to accidents, and tend to suffer a lot more with faulty power supply cables and connectors, short-lived batteries and can also overheat if poorly designed.

The choice is yours: if you travel regularly and need to take your computer with you, then a laptop is clearly an essential. If that's you, then we recommend Novatech. Otherwise, you should think carefully before deciding to buy one.

Or maybe a Netbook?

Netbooks are now being sold everywhere. They are a small laptop running on lower power and more efficient components. Netbooks are excellent for computing on the move, but generally their smaller screens and lower performance will leave the average user looking for more.

What processor?

The headline grabbing figure, particularly on eBay, is the processor (or CPU). Beware of sellers who describe a multi-core machine with deceptive language. A three-cored 3.0GHz CPU does not give you 9GHz of processing power! Neither does a dual-cored 2.5GHz CPU give you 5GHz of power. We've seen a number of computers described in such a way.

Generally, the higher the processor speed, the better - but you must also consider the levels of L1 and L2 cache. This is exceptionally fast memory (particularly L1) that resides wholly on the CPU. CPUs only provide a very small amount of it (especially in comparison to system memory), but the more of it, the better. L1 and L2 cache, however, is expensive!

How L1 and L2 cache combine with processor speed is crucial. Budget ranges of processors can provide a decent GHz rating, one that may even be favourable when compared with a much higher-end processor, but they may have much less L1 cache, for example. Once again, this is a trade-off that the average user must decide.

Some budget processors, particularly the Intel Celeron range, now provide excellent performance compared to when they were first launched, particularly if you do not use your PC for gaming.

Memory

Just like processors, memory, also known as RAM, has a great deal of variety, and, just like processors, memory has a speed rating.

However, it doesn't end there. Memory speed is usually given in two numbers, for example, DDR2 800 MHz/PC2-6400. This particular speed of memory is a very good choice for almost all PC usage. Lower ratings of 667 MHz/PC2-5300 are acceptable, but anything below this should be avoided.

PCs on the high street frequently don't tell you what speed the memory is. Some retailers prefer instead to concentrate on memory capacity - but because they don't tell you the memory speed, they can get away with installing inferior quality chips! Beware!

1GB of RAM is the absolute minimum, but 2GB is recommended, especially for Windows 7, and 4GB+ is optimum for gaming. However, to achieve any memory of more than 3.5GB, the computer needs to be running a 64-bit version of operating system (more on this later!)

A further complication is that the best performance from memory usually comes from installing memory in pairs of chips, to gain the maximum benefit from the so-called "dual channel" way in which motherboards (more on those later!) and memory communicate. This means that if you want 2GB of memory, you need two identical 1GB chips. There's no guarantee that a high street PC will have installed the memory in such a fashion. If they haven't - and, for example, it says it's a 2GB machine but there is only one stick of 2GB memory in it then the machine will be needlessly crippled because of poor construction.

DDR2 is also available in 1066MHz/PC2-8500 and slightly higher, but bleeding edge machines now have DDR3 memory, the next generation, starting at 1333MHz/PC3-10666. There are faster chips, going up to 2000MHz/PC3-16000 - but these are expensive and, in non-Intel Core i3/5/7 machines, are unnecessary because the CPU cannot keep up. Suffice to say that, for most purposes, the top end of DDR2 and the start of the DDR3 market is a good place to be for the vast majority of PC users.

Hard drives

It doesn't get any easier here! Superficially, it may look good to be getting a hard drive with huge amounts of space, but the technology of the drive interface is important, as is the spin speed, and the onboard cache of the drive.

Most hard drives should be what is known as SATA. This is the current interface via which the motherboard communicates with the hard drive. If the description doesn't say this, avoid: it will probably mean the system uses an obsolete technology (known as EIDE) and this will give poor performance. Ideally, you're looking for SATA "2.0" 300 - which is slightly faster than the original SATA specification.

Spin speed is measured in revolutions per minute (rpm) - and you should be looking for at least 7,200rpm. Cache memory is measured in MB, and though there isn't a great deal of difference for a PC with only one drive, it is slightly more advantageous to have at least 8MB of cache on a 160GB drive, 16MB of cache on a 320GB drive, and so on in similar proportions.

Depending on how much multimedia you download to your PC (music, videos, photos) you should be looking for at least 200GB of hard drive space, but increased capacity is now very common due to the ever decreasing cost of storage. Even if you run low on space, you can buy extremely simple large capacity USB drives on the high street that you can plug into your computer and store your photo albums on, for example. Some of these drives may even use a variant of the SATA technology (called eSATA) which will allow you to achieve speeds as quick as your internal hard drive - though your computer has to be able to support it.

Once again, these variations in the technology are often overlooked by high street PC retailers. It's very easy to save money by purchasing low spin speed, low cache, hard drives, especially if their size is still large enough to deflect attention. But bear in mind that the major limiting factor to higher performance on a PC is not the CPU or the memory, it's the hard drive. Failure to invest wisely on this part of the PC could render even the most expensive other components useless!

Motherboard

The motherboard is an essential component, and there are a large number of manufacturers. It can be an extremely basic model with limited options for expansion (few USB ports, no FireWire, inferior sound ability, no eSATA, for example), or it can have a huge range of abilities. More likely it will be somewhere inbetween.

A decent motherboard is a pre-requisite because every component is connected to it. If the motherboard can't keep up with the CPU, or the memory, then it will be forced to slow everything down to the speed of the weakest link.

Motherboards have a great deal of variety in terms of the components on them. A good board is likely to be in the price range of £50-70, though there are notable exceptions in the budget models - for instance we've seen motherboards as low as £40 that do the job surprisingly well.

Most motherboards now come with onboard sound, meaning you don't need to buy a separate sound card. They may also come with onboard graphics support - more on that shortly. But, as you might expect, if these are provided, they're nothing special, yet do the job for the average non-gamer. Otherwise, for those with specialist needs (audio lover, multimedia editing, extreme gaming) - you probably will need to buy a separate sound or graphics card.

Graphics card

This is complicated territory because of the vast range of manufacturers. Most cards are either ATI or nVidia at the heart, but the card itself and the remaining technology is usually made by someone else, who themselves use their own methods and components.

For the average user, not bothered about gaming, this part of a PC can generally be overlooked, as the retailer will supply a PC with a built in graphics controller. While these are totally inadequate for gaming, they should support the various spiffy graphics PCs generate these days.

Gamers, on the other hand, will be looking for a specific card that does exactly what they need: handle fast moving 3D graphics at smooth frame rates. We always ensure our PCs targeted at gamers, the Gaming and the Ultimate PCs, have an appropriate card to match their value.

Operating system

Earlier we referred to computers with more than 3.5GB of memory needing a 64-bit operating system. This is because the previous technology of computing (32-bit) has run its course and been replaced. However, at the moment there are 64-bit processors being sold on computers running a 32-bit operating system - the result of which is that the processor does not reach its full potential.

For the most part this is not a major problem, but it can be if you have 4GB of memory. If you do, your shiny new PC will only tell you it has 3.5GB (or worse, 3GB!) if you are running the standard 32-bit editions of Windows XP, Vista or 7.

To get the full benefit, you must run Windows XP 64-bit/x64 edition (not recommended) or Vista/7 Home Premium 64-bit edition.

We fully endorse the work Microsoft have put into Windows 7, so much so that we are now offering it instead of Windows Vista. We will continue to offer Windows XP for the foreseeable future, however, as a lower cost alternative that still delivers a good computing experience.

Alternatively, if you're looking for a challenge, and one that won't cost the Earth, you may wish to look into Ubuntu - a free, powerful operating system that is looking more and more appealing as a replacement for Windows.

DVD drives

Most machines these days come with, as a minimum, a DVD/CD drive which also can write as well as read. There isn't a great deal of variety in this field apart from the speed of the writing, or the ability to "write" on the cover of the disk to create a nice image (a technology known as LightScribe). For the average user, take a break from surfing specifications.

Summary

These are what we recommend for different types of PC user:

Basic User - 2.7GHz AMD Sempron CPU (Single Core), 1GB RAM, 150 GB hard drive - Basic PC

Average User - 2.7GHz Intel Pentium Dual Core, 2GB RAM, 460 GB hard drive - Standard PC

Power Use - 2.93GHz Intel Core 2 Duo E7500, 4GB RAM, 580 GB hard drive - Performance PC

Gamer - 2.5GHz Intel Core 2 Quad, 4GB RAM, 680 GB hard drive - Gaming PC

You Want It All - 2.66GHz Intel Core i5, 4GB DDR3 RAM, 920 GB hard drive - Ultimate PC

Conclusion

PCs can be an exceptionally confusing world, and the fast pace of change means you need to stay on top of what's going on if you want to have a hope of putting together the components in a way that maximises their performance. A PC can only be as good as its slowest component - so the combination of all the above is what actually delivers the end product, not the individual parts themselves. Who cares about your £200 processor if it's running on a £30 motherboard!

The key point to remember is this: the high street retailers gloss over many key factors when describing a PC. The question you must ask yourself is - why? Do they have something to hide? In many cases, they do.

At ElpaTech, we have nothing to hide because we're confident in our products. We give you all the information: and we've even written this guide to try and help you understand what it all means! We hope it's proved useful to you.

As always with these things, as the old saying goes, you pays your money and you takes your choice. With a PC you need to be reasonably well informed in order to make a good choice. And if you're not informed, then you might as well go shopping blindfolded.

We'll be happy to advise you on all the hand-built products from our range and can also custom build a machine to your exact requirements. You can contact us for a no-obligation discussion.