Which motherboard form factor uses a riser card for expansion instead of having expansion slots directly on the motherboard?

The NLX motherboard form factor is distinct for utilizing a riser card for expansion slots, which allows for the addition of expansion cards such as graphics cards, network cards, and sound cards. This design provides a unique configuration that offers flexibility in the arrangement of components, promoting improved airflow and space management within the computer case.

In an NLX configuration, the riser card connects to the motherboard and extends outward, creating a horizontal plane for expansion cards. This leads to a more compact system design, especially important in situations where space is at a premium. Using a riser card instead of directly integrating expansion slots into the motherboard can simplify upgrades and repairs by making it easier to access the expansion cards without requiring the removal of the entire motherboard.

The other form factors listed—ATX, Micro ATX, and ITX—feature expansion slots directly mounted on the motherboards themselves, which is a standard practice for these designs. Therefore, they do not employ the riser card method, making NLX unique in this context.