Preliminary - PLX Confidential

x4

x4

CPU

CPU

CPU

CPU

CPU

CPU

CPU

CPU

PEX 8616

PEX 8616

PEX 8616

PEX 8616

x4

Memory

Memory

Memory

Memory

x16

x16

x4

Chipset

Chipset

Chipset

Chipset

Endpoint

Endpoint

Endpoint

Endpoint

PCIe Gen1 or PCIe Gen2 slots

Endpoint

Endpoint

Endpoint

Endpoint

Figure 3. Fan-in/out Usage

Network Interface Cards

The PEX 8616 can also be utilized in communications

applications such as Network Interface Cards (NICs).

NICs, like the one shown in Figure 4, can utilize the

PEX 8616 for its fan-out capabilities. In the example

below, the PEX 8616 is being used on a Dual-port 10-

Gigabit Ethernet (GE) NIC card. The PEX 8616 utilizes

a x8 link to connect to the host and two x4 downstream

links to fan-out to the 10GE ports. The peer-to-peer

communication feature of the PEX 8616 allows the

endpoints to communicate with each other without any

intervention or management by the host.

10 GE

10 GE

MAC/PHY

MAC/PHY

MAC/PHY

MAC/PHY

MAC/PHY

MAC/PHY

MAC/PHY

MAC/PHY

x8

x4

x4

Dual-Port NIC

Dual-Port NIC

PEX 8616

PEX 8616

PEX 8616

PEX 8616

Figure 4. 10GE NIC Fan-Out

Host Bus Adapters

The PEX 8616 is well suited for Host Bus Adapter cards

(HBAs) as well. Figure 5 shows a Quad-Port Fibre

Channel HBAs utilizing the PEX 8616 to allow

connectivity to two Fibre Channel (FC) controllers. The

PEX 8616 uses a x8 link on the upstream port and two

x4 downstream links to fan-out to the FC Controllers

Each FC controller supports two FC ports.

x8

x4

x4

Quad-Port FC HBA

Quad-Port FC HBA

PEX 8616

PEX 8616

PEX 8616

PEX 8616

FC

FC

FC Cont.

FC Cont.

FC Cont.

FC Cont.

FC

FC

FC Cont.

FC Cont.

FC Cont.

FC Cont.

Figure 5. Quad-Port Fibre-Channel HBA

Failover Storage Systems

The PEX 8616’s Dual Cast feature proves to be very

useful in storage systems. In the example shown in

Figure 6, the Dual Cast feature enables the PEX 8616 to

copy data coming from the host to two downstream ports

(see yellow traffic patterns) in one transaction as

opposed to having to execute two separate transactions

to send data to the redundant chassis. By offloading the

task of backing up data onto the secondary system,

processor and system performance is enhanced. The

PEX 8616’s NT port is used to isolate the backup system

from the primary system.

x4

CPU

CPU

CPU

CPU

CPU

CPU

CPU

CPU

Memory

Memory

Memory

Memory

Chipset

Chipset

Chipset

Chipset

CPU

CPU

CPU

CPU

CPU

CPU

CPU

CPU

PEX 8616

PEX 8616

PEX 8616

PEX 8616

x4

PEX 8616

PEX 8616

PEX 8616

PEX 8616

NT

Memory

Memory

Memory

Memory

Chipset

Chipset

Chipset

Chipset

8 Disk Chassis

PEX 8616

PEX 8616

PEX 8616

PEX 8616

8 Disk Chassis

FC

Control

FC

Control

FC

Control

FC

Control

FC

Control

FC

Control

FC

Control

FC

Control

FC

Control

FC

Control

FC

Control

FC

Control

FC

Control

FC

Control

FC

Control

FC

Control

NT

PEX 8616

PEX 8616

NT

PEX 8616

PEX 8616

PEX 8616

PEX 8616

NT

x4

x4

x4

x4

x4

x4

x4

x4

x4

Backup

System

Figure 6. Dual Cast in Storage Systems