2–Planning
Performance
59265-02 B 2-3
PerformanceThe QLogic 5800V Series switch supports class 2 and class 3 Fibre Channel
service at transmission rates of 1, 2, 4, 8,10, or 20Gbps with a maximum frame
size of 2148 bytes. Each Fibre Channel 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
SFP transceivers that are compatible with the cable type, distance, Fibre Channel
revision level, and the device adapter. Each SFP port is supported by a data buffer
with a 16-credit capacity; that is, 16 maximum-sized frames. Tabl e 2-2 lists the
approximate transmission distances at full bandwidth over fiber optic cables:
With Enterprise Fabric Suite, longer distances can be spanned at full bandwidth
on SFP ports by extending credits to G_Ports, F_Ports, and E_Ports. Each port
can donate 15 credits to a pool from which a recipient port can borrow. However,
SFP ports can borrow only from other SFP ports. XPAK ports cannot borrow or
donate credits. The recipient port also loses a credit in the process. For example,
you can configure an SFP recipient port to borrow 15 credits from one donor port
for a total of 30 credits (15+15=30).
Table 2-2. Port Transmission Distances
Transmission Distance Port Speed Credits/Km
26 kilometers 1Gbps 0.6
13 kilometers 2Gbps 1.2
6 kilometers 4Gbps 2.4
3 kilometers 8Gbps 4.8