LPX Form Factor

One power supply form factor that has given Baby AT a run for its money over the last 15 years has been the LPX form factor. The "LP" in "LPX" stands for "low profile", another name given to these power supplies. They are also often called "slimline" power supplies because LPX cases are often called slimline cases, and "PS/2" power supplies after the famous IBM model. The main goal of this form factor is size reduction. The height in particular of the power supply is significantly reduced, facilitating the design of much smaller, consumer-oriented PCs. The connectors of the LPX form factor power supply are the same as that of the Baby AT and AT.

Diagram of the side and rear views of an LPX form factor power supply,
with approximate dimensions. Note the much smaller height dimension
compared to the AT or Baby AT form factors; the power cord outlet
and monitor pass-through have been moved next to the power supply
fan vent instead of below it. This is key to allowing the production of
smaller, "slimline" PC systems. Many LPX systems no longer have the
monitor pass-through. All of these systems use remote power switches.

Original image � PC Power & Cooling, Inc.
Image used with permission.

While never officially specified as a standard, the LPX or "slimline" power supply basically became one anyway. Due to its small size and convenient rectangular shape, these power supplies were put into all sorts of cases; not just LPX cases but Baby AT and even full-sized AT cases. Until the rise of its anointed successor, NLX, LPX systems were made in large quantity, and millions of these power supplies are still in use.

Rear view of an LPX power supply, showing its power
cord and motherboard and drive connectors.

Image � Enlight Corporation
Image used with permission.