Introduction to Computers Cases and Motherboard Form Factors

Form factors Motherboards come in different form factors: specifications that determine the motherboard’s dimensions, location of mounting holes, back panel ports and expansion slots The motherboard form factor will dictate case dimensions. Cases will be marked with compatible form factors

ATX Form Factor Stands for Advanced Technology EXtended Also called Standard ATX Dimensions: 9.6 Inches by 12 Inches Back panel dimensions: 6.25 inches by 1.75 inches Up to seven expansion slots

MicroATX Maximum size is 9.6 inches by 9.6 inches Has up to four expansion slots Adheres to ATX standards for mounting hole locations and back panel port arrangement

EATX Stands for Extended ATX Maximum size is 12 inches by 13 inches Uses the extra space for additional memory modules

Mini ITX Stands for Information Technology EXtended Dimensions: 6.7 inches by 6.7 inches Designed to be low power and low temperature boards used in smaller computers Follows ATX mounting hole and back panel arrangement to allow for compatibility with ATX cases

BTX Stands for Balanced Technology EXtended Dimensions: 9.6 Inches by 12 Inches Designed to have better heat control and air flow Didn’t catch on due to case designers needing to accommodate a new standard, and customers not needing an air flow efficient motherboard

NLX Stands for New Low-Profile EXtended Dimensions: Between 10 inches by 8 inches and 13.6 inches by 9 inches Designed with a riser card to allow expansion cards to be parallel to the motherboard

Case Form Factors Case designs are not as standardized as motherboards, but there are guidelines when choosing a case Most importantly, make sure the dimensions of your motherboard fit in the case by matching form factors.

ATX Full tower Gives access to several external bays Fit all ATX form factors including EATX Lots of room for large graphics cards and hard drives Good air flow Large and bulky. Mostly placed under desks

ATX Mid tower Gives access to multiple external bays Fit most ATX form factors, typically excluding EATX Less space than full tower, but still large enough to accommodate most user’s needs

micro-ATX tower Gives access to fewer external bays Fits micro ATX and mini ITX motherboards Used when space, price or portability is a concern

micro-ATX tower Typically gives access to one external bay Fits mini ITX motherboards Used when space, price or portability is a concern even beyond micro-ATX Popular as a home theater PC due to it’s small size