Installation guide
2–Planning
Performance
59229-05 A 2-3
Performance
The QLogic 9000 Series switch supports class 2 and class 3 Fibre Channel 
service at transmission rates of 1-, 2-, 4-, 8-, and 10-Gbps with a maximum frame 
size of 2148 bytes. A port adapts its transmission speed to match that of the 
device to which it is connected prior to login when the connected device powers 
up. Related performance characteristics include the following:
 Distance
 Bandwidth
 Latency
Distance
Consider the physical distribution of devices and switches in the fabric. Choose 
transceivers that are compatible with the cable type, distance, Fibre Channel 
revision level, and the device host bus adapter. Refer to Appendix A for more 
information about cable types and transceivers.
Each SFP and X2 port is supported by a data buffer with a 16 credit capacity; that 
is, 16 maximum sized frames. For fibre optic cables, this enables full bandwidth 
over the following approximate distances:
 26 kilometers at 1-Gbps (0.6 credits/Km)
 13 kilometers at 2-Gbps (1.2 credits/Km)
 6 kilometers at 4-Gbps (2.4 credits/km)
 3 kilometers at 8-Gbps (4.8 credits/km)
 2 kilometers at 10-Gbps (7.2 credits/km)
Longer distances can be spanned at full bandwidth on SFP ports and X2 ports by 
extending credits to G_Ports, F_Ports, and E_Ports using Enterprise Fabric Suite 
2007. Each port can donate 15 credits to a pool from which a recipient port on the 
same I/O blade can borrow. The recipient port also loses a credit in the process. 
For example, you can configure a recipient port to borrow 15 credits from one 
donor port for a total of 30 credits (15+15=30).
Ports can borrow credits from other ports of like kind: SFP ports can borrow from 
SFP ports; X2 ports can borrow from X2. However, SFP ports cannot loan or 
borrow credits from X2 ports.










