1. Introduction to Computers
Cases and Motherboard Form Factors

2. 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

3. 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 inches
Up to seven expansion slots

4. 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

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

6. 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

7. 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

8. 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

9. 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.

10. 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

11. 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

12. 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

13. 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