Compaq ProLiant 1000 I/O Performance Tuning of Compaq Servers - Page 8

I/O Performance Tuning of Compaq Servers 8 3. Avoid putting two network controllers together in the same bus unless both busses already have a network controller installed. Note thatSince fewer devices can lower contention, it is generally better to have a system with one dual-port NIC in each bus than to have two single-port NICs in each bus. 4. When adding redundant NIC pairs, place both NICs on the same bus. If the server was to failover to the backup device the load would remain balanced. Primary PCI Bus 133MB/s Microprocessor Motherboard Chipset 266MB/s System Memory 133MB/s PCI Slot PCI Slot PCI Slot PCI Slot PCI Slot PCI Slot PCI Slot PCI Slot Secondary PCI Bus Figure 3. Peer PCI Architecture These guidelines should not be followed if one device consistently operates at a higher load. If, for example, one particular NIC operates at or near its upper limit while 3 other NICs in the same server remain relatively idle, you should not split the number of NICs evenly. In this case, you should attempt to balance the loads by placing the heavily loaded card in one bus and the less active NICs in another bus. Balancing the total load on the PCI bus, from all devices, is the key to maximizing PCI throughput. Table 1. PCI Bus Architectures of ProLiant servers PCI Slot Number 1 2 3 4 5 6 7 8 9 10 11 Bridged PCI Bus Systems Peered PCI Bus Systems ProLiant 2500 ProLiant 1200 ProLiant 1600 ProLiant 3000/ ProLiant 5000 ProLiant 6000/ ProLiant 5500 ProLiant 7000 Secondary Secondary Secondary Primary Secondary Secondary Secondary Primary Secondary Secondary Secondary Secondary Primary Secondary Primary Primary Primary Primary Primary Secondary Primary Primary Primary Primary Secondary Primary Primary Primary Primary Primary Secondary Primary Primary Secondary Primary Secondary Secondary Primary Secondary Secondary Secondary Secondary ProLiant 6500 Primary Primary Secondary Secondary Secondary Secondary Secondary Secondary ECG044.0399