MSB7890 IB Switch 2 support for Qlogic passive cables (CBL1-0600328)?

Hi, we purchased earlier this year a new unmanaged MSB7890 and ConnectX-3 Pro VPI adapter cards.

We tested the cards first in a few boxes and they worked fine with our older Qlogic switch and cables. Recently the new Mellanox switch was installed using the same cables. We also have a handful of Mellanox cables, and noticed only these ones were showing the physical link led on the switch and effectively bringing up the interface. There was no luck at all with the Qlogic ones.

I’m adding below some output I got with MST, which we also forwarded to our supplier. I thought initially the firmware version of the switch was the cause (15.1430.0160), but they ruled it out. They said “it must be something with the coding of the SFPs on the cables”:

  • Mellanox Switch:

Device Type: SwitchIB2

Part Number: MSB7890-Exxx_Ax

Description: Switch-IB 2 based EDR InfiniBand 1U Switch; 36

QSFP28 ports; unmanaged; RoHS6

PSID: MT_2640110032

PCI Device Name: SW_MT53000_SwitchIB_Mellanox_Technologies_lid-0x0002

Base GUID: 1c34da0300082da0

Versions: Current Available

FW 15.1430.0160 N/A

  • Mellanox PCI Cards in computer nodes:

Device Type: ConnectX3Pro

Part Number: MCX353A-FCC_Ax

Description: ConnectX-3 Pro VPI adapter card; single-port QSFP; FDR IB (56Gb/s) and 40GigE; PCIe3.0 x8 8GT/s

PSID: MT_1100111019

PCI Device Name: 21:00.0

Port1 GUID: 1c34da03000236e1

Port2 MAC: 1c34da0236e1

Versions: Current Available

FW 2.42.5000 2.42.5000

PXE 3.4.0752 3.4.0752

  • Passive copper Cables:

Qlogic P/N CBL1-0600328 (Manufacturer no: Amphenol - 584470004)

Here’s the partial output of the ‘mxlcables’ command, after I added the cables, which shows how the switch detects them:

Cable #37:

Cable name : SW_MT53000_SwitchIB_Mellanox_Technologies_lid-0x0002,mlx4_0,1_cable_5

No FW data to show

-------- Cable EEPROM --------

Identifier : Unrecognized identifier (0ch)

Technology : Copper cable unequalized (a0h)

Compliance : Unspecified, QDR

Attenuation : 2.5GHz: 7dB

5.0GHz: 11dB

7.0GHz: 0dB

12.9GHz: 0dB

25.78GHz: 0dB

OUI : 0x415048

Vendor : Amphenol

Serial number : APF12060042GUN

Part number : 584470004

Revision : D

Temperature : 1 C

Length : 3 m

Cable #38:

Cable name : SW_MT53000_SwitchIB_Mellanox_Technologies_lid-0x0002,mlx4_0,1_cable_4

No FW data to show

-------- Cable EEPROM --------

Identifier : QSFP+ (0dh)

Technology : Copper cable unequalized (a0h)

Compliance : Unspecified, QDR,DDR,SDR

Attenuation : 2.5GHz: 5dB

5.0GHz: 8dB

7.0GHz: 0dB

12.9GHz: 0dB

25.78GHz: 0dB

OUI : 0x0002c9

Vendor : Mellanox

Serial number : MT1438VS03133

Part number : MC2206130-002

Revision : A3

Temperature : N/A

Length : 2 m

I could not find anywhere any info on the compatibility with these cables, but we wonder if there is anything else to do other than getting new cables and cursing our supplier for not giving proper advice. Let me know if I should add any other info.


Hello Pip,

Thank you for posting your inquiry on the NVIDIA Networking Community.

Based on the information provided, unfortunately we only support Mellanox cables used with our switches. You can find the appropriate cable through our LinkX configurator →

Thank you and regards,

~NVIDIA Networking Technical Support