LPX and Mini LPX

Conventionally used in mass-produced "name brand" retail systems, the LPX motherboard form factor goes into the small Slimline or "low profile" cases typically found on these sorts of desktop systems. The primary design goal behind the LPX form factor is reducing space usage (and cost). This can be seen in its most distinguishing feature: the riser card that is used to hold expansion slots.

Instead of having the expansion cards go into system bus slots on the motherboard, like on the AT or ATX motherboards, LPX form factor motherboards put the system bus on a riser card that plugs into the motherboard. Then, the expansion cards plug into the riser card; usually, a maximum of just three. This means that the expansion cards are parallel to the plane of the motherboard. This allows the height of the case to be greatly reduced, since the height of the expansion cards is the main reason full-sized desktop cases are as tall as they are. The problem is that you are limited to only two or three expansion slots!

LPX form factor motherboards also often come with video display adapter cards built into the motherboard. If the card built in is of good quality, this can save the manufacturer money and provide the user with a good quality display. However, if the user wants to upgrade to a new video card, this can cause a problem unless the integrated video can be disabled. LPX motherboards also usually come with serial, parallel and mouse connectors attached to them, like ATX.

While the LPX form factor can be used by a manufacturer to save money and space in the construction of a custom product, these systems suffer from non-standardization, poor expandability, poor upgradability, poor cooling and difficulty of use for the do-it-yourselfer. They are not recommended for the homebuilder, but if you are upgrading one of these systems, you may not have many alternatives.