- 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
Universal Serial Bus
Universal Serial Bus (USB) is a standard for connecting peripheral devices to a computer. It was designed to replace PS/2, serial and parallel connections (which can still be found on many motherboards). The first incarnation of USB, version 1.1 operates at up to 12Mbps (which means the peripherals can talk to the computer, and vice versa, at 12Mbps), while USB 2.0 delivers up to 480Mbps.
With USB, you can often connect one device to another in a daisy-chain fashion. Thus, a mouse can connect to a keyboard instead of plugging into the back of the computer. And that keyboard can connect to a USB port in the monitor. If you need more USB ports, just connect a hub and, in theory, up to 127 USB devices can be interconnected.
Low power USB devices can sometimes be directly powered from the PC's power source via the USB connection, but only when the device draws less than 5V.
You would expect to see at least 4 USB ports on the rear faceplate of a motherboard but today's mid-to-high-end motherboards can have up to 12 ports. Usually, at least two ports can be found at the front of a PC case for convenient access.
IEEE 1394, which is commonly referred to as FireWire (but also as i.Link by Sony), is used to connect devices such as digital video cameras and external hard drives to your PC at a speed of 400Mbps. FireWire supports up to 63 devices on a single bus. Most mid-range PCs will ship with a FireWire port, as will high-end PCs, but budget systems usually don't have a FireWire port installed. If your PC doesn't have a FireWire port, and you need to connect your DV camcorder, then you'll need to install a FireWire expansion card (either PCI- or PCI Express-based).
A newer version of FireWire is referred to as IEEE 1394b, but hardly any PCs come with this interface. The architecture of the new specification technically supports speeds up to 3.2Gbps, but initial implementations only work at 800Mbps. However, the biggest change for FireWire may not be the doubling of speed, but the range provided by the specification. The current version of FireWire works at a distance of 12-15 metres. The 'b' spec will increase that distance up to 115 metres.
S/PDIF (Sony/Philips Digital Interface)
Developed jointly by the Sony and Phillips corporations, S/PDIF allows the transfer of digital audio signals from one device to another without having to be converted first to an analogue format. Many motherboards come with this interface, which can be harnessed via optical or coaxial cables, depending on the motherboard manufacturer's implementation.