Note:

If your controller is running at 100 Mbps and half duplex, your potential bandwidth is higher than if you run it at 10 Mbps and full duplex.

Note:

Controller performance may suffer or your controller may not operate if your switch doesn’t support full duplex and you configure the controller to full duplex. Make sure you always set the speed when you configure duplex.

Select Duplex Mode (Optional)

Duplexing is a performance option that lets you choose how the ethernet controller sends and receives data packets over the network. The ethernet controller can operate at full duplex only when connected to a full duplex 10BASE-T, 100BASE-TX switch, or another full duplex adapter.

•Auto (requires a full duplex adapter or switch with auto- negotiation capability). The controller negotiates with the switch to send and receive packets at the highest rate. This is the default setting. If the switch does not provide auto-negotiation, the controller runs at half duplex.

•Full duplex (requires a full duplex switch or adapter). The controller can send and receive packets at the same time. This mode can increase controller performance capability. If the full duplex switch provides auto-negotiation, the controller runs at full duplex. If the full duplex switch does not provide auto-negotiation, you need to set the controller duplex mode manually (see following paragraphs), because it defaults to half duplex.

•Half duplex. The controller performs one operation at a time; it either sends or receives.

Manually Configuring for Full Duplex

If your switch supports auto-negotiation with the N-way standard, duplex configuration is automatic and no action is required on your part. However, few switches in the current installed base support auto-negotiation. Check with your network system administrator to verify whether your switch supports this feature. Most installations will require manual configuration to change to full duplex.

Configuration is specific to the driver you’re loading for your network operating system (NOS).

To set up the duplex mode, refer to the section below that corresponds to your operating system.

12 Intel EtherExpress PRO/100+ TX PCI LAN Controller User’s Guide