Asus P5B Deluxe/WiFi-AP - Manual (Page 47)

ASUS P5B Deluxe -1
We recommend that you install a VGA card on the primary (blue) PCI Express
slot, and install any other PCI Express device on the Universal PCI-E slot (black).
Primary PCI Express x16 slot
The primary PCI Express x16 slot
supports PCI Express x16 graphic
cards that comply with the PCI Express
specifications.
Universal PCI-E slot
(max. x4 mode)
This motherboard also supports a
Universal PCI-E slot with a maximum
speed of 2 GB/s. The operating
frequency of this slot changes,
depending on the type of PCI Express card you install. Refer to the table below
and page 4-23 for details.
The figure shows two graphics cards installed on the primary PCI Express x16 slot
and the Universal PCI-E slot.
If you install two VGA cards, we recommend that you plug the rear chassis
fan cable to the motherboard connector labeled CHA_FAN1 for better thermal
environment. See page 2-31 for the connector location.
• Some PCI Express graphics cards cannot operate on x4/x2 mode. We
suggest that you install these cards on the primary PCI Express slot (blue)
to increase system stability.
• Some PCI Express devices cannot operate on x4/x2 mode.
Options for Universal PCI Express operating speed
PCI Express slot
Auto Automatically optimizes performance
and functionality according to devices
installed
x4 mode [fast] User gets the best performance but this
mode disables the PCI Express x1 slot
x2 mode [compatible] Always runs at PCI Express x2 speed