Rapidly gaining acceptance among large OEM system builders, the most likely place a home builder will find these is in late-model Pentium-4 based Shuttle Cube PCs, where Nano BTX is replacing its shortened version of Flex ATX.

Intel made its push for BTX around three years ago, the major advancement being a straight CPU cooling path from the front to the back of the case. The board is reversed compared to ATX, which flips the cards over to place standard graphics coolers into the cool air stream.

BTX form factors are more rigidly defined than ATX: The CPU cooler is attached at the front of the motherboard to its mounting plate, so that all versions must have the same depth. Because the CPU area is rigidly defined, Micro, Nano and Pico BTX motherboards are able to fit larger cases if desired. BTX dimensions are based on decimal inches.

Curious readers can find a more detailed description of BTX and its advantages in our Alderwood/Grantsdale chipset preview.