Advice on buying computers
Computers come in many different shapes, sizes and formats and to the newcomer this must be very confusing. Here we will try to explain some of the jargon.
What is the difference between the £50 second hand PC and the brand new £500+ machine? Well the second hand PC would have been good in its day but the parts will be out of date and obsolete. This machine will never be able to carry out most modern day computing functions like audio or video editing and finding parts will be a nightmare. The money you spend on parts etc could buy you a new, up to date machine. Unless you only want to type up the occassional letter, these machines should be avoided.
Here we will try explain each computer part in detail
Case:
Most cases today will be in the ATX format although smaller, more compact cases (ITX / BTX) are becoming more popular especially for home theatre / media centre systems. If you plan to add more hardware in future like hard drives or CD/DVD drives then make sure you buy a case that has empty 5 1/4" spaces to support this. Otherwise you will have to transfer everything from your old case to a new one or cancel the upgrade.
**Important Points To Be Aware Of:
Full ATX mainboards will NOT fit in micro ATX cases

Mainboard:
These can be very confusing due to the amount and variations of hardware availible today. The main choice is between boards that support AMD processors and those that support Intel processors. An AMD processor will NOT fit a board designed for Intel processors and vice versa. Boards are usually identified by the type of processor slot/socket on them and this determines which type of processor they take. Here is a rough guide:
AMD Duron/Athlon - Socket A (Obsolete)
AMD 64 - Socket 754, 939
AMD 64 X 2, FX - Socket 939
AMD Sempron - Socket A, 754
Intel P3 - Socket 370
Intel P4 (Including Celeron) - Socket 478 (Becoming Obsolete), 775
Budget - Socket A, 754, 478
Mid - Socket 754, 775
Pro - Socket 939, 940

Hard Drive:
For normal everyday computing a 40 GB 7200rpm hard disk is fine. If you plan to store vast amounts of data then the bigger the better. It might even be worth while having an additional hard drive for extra storage and backups. As well as size, hard drives are also measured by their speed and buffer size. Common speeds are 7200rpm and 2MB or 8MB buffer sizes.
Newer Serial-ATA or SATA or SATA2 hard drives provide much faster data transfer and are becoming more of todays standard.
Budget - 40 - 80 GB 7200rpm 2/8MB Buffer
Mid - 80 GB+ IDE or SATA
Pro - 200GB+ SATA, SATA2
Memory:
Most memory today is of the DDR type and there are various specifications of this. DDR 400 is faster than DDR 266. Newer DDR2 memory is even faster again.
Budget - 256 MB+ DDR
Mid - 512 MB DDR
Pro - 1 GB+ DDR, DDR2
Systems are usually sold with a minimum of 128 MB memory although we recommend atleast 256 MB+ for Windows XP
Processor:
The brain of the computer and your main choice is between AMD and Intel although there are others from VIA / Cyrix. Processors also have cache memory and a bus speed. Again the higher the number the better the performance.
Budget - AMD Sempron 2600+, Intel Celeron 2GHz+
Mid - AMD Sempron 2800+, AMD 64, Intel P4 5 Series
Pro - AMD 64 FX or Dual Core, Intel P4 6 and 8 Series

Graphics:
For everyday computing or office work, on board graphics are fine. If you plan to play games, watch DVD's or do photo/video editing then we recommend getting a decent card. These cards have their own dedicated memory and the more memory the better. 2 standards of cards exist - AGP and newer, faster PCI - Express.
Budget - Onboard or cheap 64 MB+ AGP Card
Mid - 128 MB - 256 MB AGP
Pro - PCI - Express x 16 Card
CD/DVD Drives:
The basic is the CD-ROM drive which will only read CD-ROMs. Then there is the CDRW which can write data to blank CDRs. Then there is DVD-ROM drives which can read DVD disks. And finally there are DVDRW which can write to blank DVD media of atleast 4.7 GB in size.
Budget - CDROM, DVD
Mid - CDRW, CDRW/DVD Combo,
Pro - Dual Layer DVDRW
Monitors:
Again the bigger the better with TFT screens becoming more popular
Budget - 17" CRT
Mid - 15 - 17" TFT, 19" CRT
Pro - 19" TFT
Operating System:
Go for atleast Microsoft Windows XP Home. Windows 95/98/NT/2000 etc are things of the past and will only hamper your PC's performance and computing experience. Also these operating systems are not supported anymore.
Budget - XP Home
Mid - XP Pro, XP MCE 2005
Pro - Windows Server 2003
USB:
Used to connect a wide range of hardware to your PC and to each other ie printers, scanners, cameras etc. USB 2.0 is better and faster. All of our systems have atleast 4 USB2.0 ports.
Firewire:
The same idea as USB though not standard on every system.
About the Author
Stuart King I.T. Support Cyberia Systems http://www.cyberiasystems.co.uk