Chassis Design; Figure 3. Atx Chassis Mounting Holes For Pentium® 4 Processors - Intel Pentium 4 Design Manual

Intel® Pentium® 4 Processor in the 423-pin Package Thermal-Mechanical Support Design Guide
Version 1.0

2.2 Chassis Design

The retention mechanism is attached to the chassis via four (4) standoffs, as shown in
Figure 3. These standoffs are in addition to the standard ATX mounting holes defined in
the ATX Specification, Version 2.03. The standoffs must be removable to maintain
backward-compatibility with boards that do not support Pentium® 4 processors. The four
(4) standoffs for the retention mechanism must be the same height as the standard ATX
board standoffs and compatible with 6-32 (x 1/2 inch-3/8 inch) pan- head or round-head
screws. It is the responsibility of the chassis vendor to supply the four (4) 6-32 screws with
the chassis.
Figure 3. ATX Chassis Mounting Holes for Pentium® 4 Processors
The direct chassis-attach solution has been tested at 30 g (11 ms trapezoidal pulse)
unpackaged system shock and 50 g (11 ms trapezoidal pulse) unpackaged board shock to
allow for differences in system structural designs. It is the responsibility of the chassis and
system designer to ensure that the chassis structure does not transfer greater than 50 g
shock to the board at a 30 g system input.
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