NT200A01 and PCIe x8x8 bifurcation
2017-11-23 08:48

To enable full bandwidth using NT200A01, the PCIe slot must be a 16-lane Gen3 type and the slot must support the PCIe x8x8 bifurcation mode.
Major server vendors e.g. SuperMicro, HP, Dell, Asus have servers which support the bifurcation feature. Please see the servers below which have been tested with NT200A01 using PCIe x8x8 bifurcation. 

Super Micro: X10 DRW-IT, X10 DRC-T4+, X9DRi-F, X10SRi-F
HP: DL380 Gen9
Dell: PowerEdge R730

If NT200A01 is used with a server without bifurcation, it is also possible to detect the card as an 8-lane PCIe device in a 16-lane PCI slot. Please be advised that the throughput would be x8 PCIe throughput.
Subsystem 1 should be detected as endpoint to make NT200A01 work in a server without bifurcation support. Please see below.

< How to make it work in a server without bifurcation >
NT200A01 subdevice id = 0001 must always be enumerated.
The followings are command examples and output, when Subsystem ID = 0001 is correctly enumerated.

# lspci | grep Napa

84:00.0 Network controller: Napatech A/S NT200A01 Network Adapter

# lspci -s 84:00.0 -v
84:00.0 Network controller: Napatech A/S NT200A01 Network Adapter
        Subsystem: Napatech A/S Device 0001
        Flags: bus master, fast devsel, latency 0, IRQ 11
        Memory at fbe00000 (32-bit, non-prefetchable) [size=16K]
        Capabilities: [80] Power Management version 3
        Capabilities: [90] MSI: Enable- Count=1/32 Maskable- 64bit+
        Capabilities: [c0] Express Endpoint, MSI 00
        Capabilities: [100] Advanced Error Reporting
        Capabilities: [300] #19

If subsystem ID = 0001 is not enumerated, it is possible to reconfigure the card to operate as one 8-lane PCIe endpoint using imgctrl.

# ./imgctrl -a0 -s --pcix8
imgctrl v3.5.5.1-f24b1 (Sep 12 2017 08:02:15) (Logfile: /tmp/imgctrl.log)
Scanning for Napatech adapters..
Error: Failed opening adapter 0
  OK. PCIx8 - ONE 8-lane PCI End Point adapter configuration set.
      Server reboot is required to assert new PCI configuration.
# reboot

Note: We have observed that the x8 configuration does not work, if the system fails to enumerate NT200A01 subdevice 1. This operation must be done in a system, which is able to enumerate NT200A01 subdevice 1.

Note: Detecting NT200A01 as an 8-lane device in a server which does not support bifurcation is supported by Huntington Beach 1 FPGA + driver (Package 8.0.1, driver 3.4.1, NT200A01 FPGA 9508-06-06) and newer versions. i.e. NT200A01 will be detected as an 8-lane device in a 16-lane slot.

Jackie Han 2017-11-23 14:08

Please also see the bifurcation supported server list in the intranet. https://intranet.napatech.com/support?do=#bifurcation_supported_servers (Accessible only by Napatech staff. Please submit a ticket to get the server list, if you are not staff.)