Hardware Reference
In-Depth Information
Figure 4.9
Typical NLX motherboard rear connector layout.
AlthoughNLXisastandardformfactor—justastheATXfamilyis—mostNLXproducts
were sold as part of complete systems aimed at the corporate market. Few aftermarket
motherboardshavebeendevelopedinthisformfactor.ThemicroATXandFlexATXform
factors have superseded NLX in the markets formerly dominated by LPX.
WTX
WTX was a board and system form factor developed for the mid-range workstation mar-
ket; however, most vendors making workstations and servers have used the ATX form
factor. WTX went beyond ATX and defined the size and shape of the board and the inter-
face between the board and chassis, as well as required chassis features.
WTX was released in September 1998 (1.0) and updated in February 1999 (1.1). Since
then,however,WTXhasbeenofficiallydiscontinued,andtherewillbenofurtherupdates.
BTX
Balanced Technology Extended (BTX) is a motherboard form factor specification that In-
tel released in September 2003, with 1.0a and 1.0b updates released in February 2004
and July 2005, respectively. BTX was designed to address the ever-increasing component
power and cooling requirements, as well as enabling improved circuit routing and more
flexible chassis designs. However, the recent trend toward more power efficient dual-
