Q-Logic 2-8C Manuel D’Utilisation

3 – Planning

Performance

59042-06 A

3-5

3.3.2

Bandwidth

Bandwidth is a measure of the volume of data that can be transmitted at a given
transmission rate. A port can transmit or receive at 1-Gbps or 2-Gbps depending
on the device to which it is connected. The switch supports all transmission rate
combinations as shown in

Table 3-2

In multiple chassis fabrics, each link between chassis contributes 100 or 200
megabytes of bandwidth between those chassis. When additional bandwidth is
needed between devices, increase the number of links between the connecting
switches. The switch guarantees in-order-delivery with any number of links
between chassis.

3.3.3

Latency

Latency is a measure of how fast a frame travels from one port to another. The
factors that affect latency include transmission rate and the source/destination
port relationship as shown in

Table 3-3

Table 3-2. Port-to-Port Transmission Combinations

Source Port Rate

Destination Port Rate

Maximum Bandwdith

1-Gbps

100 MB

1-Gbps

2-Gbps

100 MB

1-Gbps x 2 ports

2-Gbps

200 MB

2-Gbps

1-Gbps x 2 ports

100 MB each port

Bandwidth will be less for larger sequence sizes.

2-Gbps

200 MB

Table 3-3. Port-to-Port Latency

Source/Destination Rates

Same Switch I

1-Gbps – 1-Gbps

< 1 µsec

2-Gbps – 2-Gbps

< 0.4 µsec