Asus P5Q Premium - Manual (Page 30)

2-4 Chapter 2: Hardware information
2.2.3 Placement direction
When installing the motherboard, make sure that you place it into the chassis in the
correct orientation. The edge with external ports goes to the rear part of the chassis
as indicated in the image below.
2.2.4 Screw holes
Place nine (9) screws into the holes indicated by circles to secure the motherboard
to the chassis.
Place this side towards
the rear of the chassis
DO NOT overtighten the screws! Doing so can damage the motherboard.