Expansion Slots, Cards, and Bays: Choosing the right computer case

An expansion card in computing is a printed circuit board that can be inserted into an expansion slot of a computer motherboard to add additional functionality to a computer system.

One edge of the expansion card holds the contacts that fit exactly into the slot. They establish the electrical contact between the electronics (mostly integrated circuits) on the card and on the motherboard.

Connectors mounted on the bracket allow the connection of external devices to the card. Depending on the form factor of the motherboard and computer case, around one to seven expansion cards can be added to a computer system. There are also other factors involved in expansion card capacity. For example, some expansion cards need two slots like some NVidia GeForce FX graphics cards and there is often a space left to aid cooling on some high end cards.

Expansion Bays and Upgrading your Computer

Expansion bays are an important factor to consider when modding your PC and upgrading the case to something more verstile as well as aethetically pleasing (or shocking!)

You need to choose your computer case to allow for plenty of upgrade room and expansion. Even though your are probably 100% happy with the size and performance of your computer today, you will surely want to plug in the latest toys and drives when they become available.

Therefore you should look for a computer case that has more bays than you need for expansion. After you floppy, internal hard drive, cd rw, and dvd-ROM you should leave some room for at least one expansion such as an extra hard drive to backup your main or another burner so you can make cd to cd copies without swapping out.

Computer Modding

Popular modifications include coloured cases, case windows to peek inside (usually made out of plexiglass), coloured lights that illumainate the case and make it glow (these are usually cold cathode lights, neon lights or LEDs (any light that does not emit heat is good - we want to avoid adding extra heat to the case where possible)), fans with lights, non-standard motherboard colours (most motherboards are dark green), LCD status panels, pictures on the glass, plus case stickers. The more dedicated modders turn their case into a work of art or create their own case with a special material or appereance. Watercooling is also a kind of Case Modding. --- Paul LoIacono is the president and owner of ATX Cases. You can see a wild array of computer case shapes, sizes and designs by visiting

Paul LoIocano