- The PC processor
- Intel processors
- AMD processors
- Dual processors and multi-core processors -- a dual-core CPU
- The motherboard
- Motherboards for AMD and Intel
- Graphics controller
- Hard drive
- PC case
- Sound cards
- Speaker systems
- Media centre PCs
- Questions to ask the retailer
A port for a 3.2mm audio jack, usually green, used to connect external headphones. Usually located at the rear of the PC on the motherboard, but most new PCs will also have one located at the front of the case.
Similar to the headphone jack, this is a (usually pink) 3.2mm audio port to connect external microphones. A microphone port can also usually be found on the front of the case.
A connection that is used to input an audio signal into your PC. For example, you can connect your stereo's CD player to it and listen to it through your PC. Simply connect an audio lead from your CD player through to the sound card and you'll be able to listen to your CD player through the speakers connected to your PC.
A 25-pin data transfer port that's used for connecting printers. This isn't an essential port as all new printers now use USB.
Game controllers and older-style dial-up modems would normally use this type of 9-pin connection. Serial ports can still be found on many motherboards, but they are rarely needed. Users who have specific needs, such as downloading data from digital multimeters or other specialist devices, should make sure their PC has one.
Typically used for connecting a mouse and keyboard. Easy to identify, these 6-pin ports are often coloured green for mice, purple for keyboard.
Random Access Memory (RAM) is the term used to describe memory found on PCs or graphics controllers (more on this later). Memory is incorporated into a desktop PC via memory modules, which connect through dedicated memory slots on the motherboard.
The most commonly used type of RAM in PCs is Double Data Rate (DDR) SDRAM and there are currently two types that you need to look out for: DDR2 and DDR3. These are physically different so a PC designed for DDR2 memory modules won't be able to use DDR3 modules and vice versa. For AMD-based PCs, DDR2 is required, while Intel-based PCs can use either type of memory, but not both at the same time.
Memory speeds for DDR2 memory start from 533MHz, but the most common speed is 800MHz. Some motherboards can support DDR2 speeds up to 1066MHz and higher. The faster the memory speed, the more data the CPU will be able to move at any one time, thereby increasing PC performance. DDR3 memory starts at around 1066MHz and can go up to around 1800MHz. It's not very popular at the moment so is therefore very expensive, and it's currently only available for some high-end Intel-based PCs.