• Frequently asked questions
• PCI Express* technology architecture for graphics
• Configuration tips
• Operating system compatibility
• Application compatibility
• PCI Express compatibility
• Form factor compatibility

Configuration Tips

Consider the following tips when integrating a PCI Express* controller into a motherboard.

Slot insertion guidelines

• A x1 connector can only take a x1 card
• A x16 connector can take a x1 through a x16 card
• A x8 connector with x4 links is physically a x8 connector and can take a x1 through a x8 card
• If a x8 card is inserted in a x8 connector with x4 links, the speed will throttle down to the speeds of a x4 card

Retention brackets

• Not mandatory for the motherboard
• PCI Express slots have a small latch for compatibility with PCI Express cards containing a retention bracket
• Card manufacturers may include in their cards if shock and vibration are considered an issue due to the silicon or fan installed on the card

Operating System/Application Compatibility

Any future improvement of PCI Express will occur in the physical layer. Compatibility with the PCI addressing model (a load-store architecture with a flat address space) is maintained to ensure all applications and drivers operate unchanged. PCI Express configuration uses standard mechanisms as defined in the PCI Plug-and-Play specification.

PCI Express Compatibility

PCI Express maintains backward compatibility with PCI to ensure that existing applications and drivers operate unchanged. The PCI configuration space and the programmability of I/O devices are key concepts that are unchanged within the PCI Express architecture; in fact, all operating systems should be able to boot without modification on a PCI Express-based platform. The run-time software model supported by PCI is a load-store, shared memory model - maintained within the PCI Express architecture in order to enable existing software to execute unchanged. The changes implemented in the PCI Express architecture affect the physical layer only.

Form Factor Compatibility

PCI Express connectors are similar in width to existing PCI connectors. They also share the same PCB dimensions, component height, and support existing ATX and server form factors. The PCI Express add-in cards follow the same height and length requirements as PCI, and utilize the same I/O bracket to secure cards to the chassis.

Related Topics

This applies to:

Intel® 82915G/82910GL Express Chipset Family Intel® 925X Express Chipset Family Intel® 945 Express Chipset Family Intel® 955X Express Chipset Intel® 975X Express Chipset Mobile Intel® 915GM/GMS, 910GML Express Chipset Family