NVIDIA ConnectX-7 Adapter Cards Firmware Release Notes v28.48.1000 (February 2026 GA Release)
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Known Issues

VF Network Function Limitations in SR-IOV Legacy Mode

Dual Port Device

Single Port Device

127 VF per PF (254 functions)

127

VF Network Function Limitations in Switchdev Mode

Dual Port Device

Single Port Device

127 VF per PF (254 functions)

127

VF+SF Network Function Limitations in Switchdev Mode

Dual Port Device

Single Port Device

  • 127 VF per PF (254 functions)

  • 512 PF+VF+SF per PF (1024 functions)

  • 127 VF (127 functions)

  • 512 PF+VF+SF per PF (512 functions)

Internal Ref.Issue
4285063Description: mlxconfig may report incorrect default INI parameter values when queried, even though the Current and Next boot values are reported correctly.
Workaround: N/A
Keywords: mlxconfig
Detected in version: 28.48.1000
4604969Description: Probe packets might be dropped at the transmission stage when multiple congestion control flows are active.
Workaround: N/A
Keywords: PCC, RTT, probe
Detected in version: 28.47.1026
4436870Description: PCIe link speed may degrade after a disable/enable operation.
Workaround: A manual retrain command is required to restore full speed.
Keywords: PCIe
Detected in version: 40.47.1026
4496642

Description: The timestamps (t2, t4) of the received RTT probes are taken from the free-running clock, even when ROCE_CC_RTT_TIMESTAMP_FORMAT is set to 0x02.

The format of all RTT probe timestamps can be found in HCA_CAP.rtt_timestamp_format.

Workaround: N/A
Keywords: RTT RTC timestamp
Detected in version: 28.47.1026
4705241Description: When Quantum-2 is part of an XDR topology, serving as a leaf switch connected to NDR-based hosts, a bandwidth degradation of approximately 3–7 Gb/s is expected.
Workaround: N/A
Keywords: XDR, NDR, Quantum-2
Detected in version: 28.47.1026
4705948Description: When using DC as the InfiniBand transport type to perform an ib_read RDMA operation between ConnectX-7 (NDR) and ConnectX-8, a bandwidth degradation of approximately 25% may be observed when using a low number of QPs (1–16). The performance degradation diminishes as the number of QPs increases.
Workaround: N/A
Keywords: DC, ib_read RDMA, NDR, performance
Detected in version: 28.47.1026
4685736Description: Creating a DPA process that allocates a 128 MB data segment and loads a dynamic library may fail with syndrome 0xdc30ac.
Workaround: Limit the DPA application’s data segment size to 64 MB.
Keywords: DPA
Detected in version: 28.47.1026
4628696Description: When HASH LAG single QP is enabled, ib_read_bw for a single QP over hash LAG can reach up to 337 Gbps, while ib_write_bw for a single QP can achieve up to 390 Gbps.
Workaround: N/A
Keywords: HASH LAG single QP
Detected in version: 28.47.1026
4657082Description: PTP holdover is not supported on FireFly without SyncE; it is available only when using Servo.
Workaround: N/A
Keywords: PTP Holdover
Detected in version: 28.47.1026
4394475Description: The existing congestion control configuration applies globally, rather than on a per-priority basis.
Workaround: Ensure that the configuration values for all priorities are aligned in either mlxconfig ROCE_CC_PRIO_MASK_P$port or sysfs ecn/roce_rp/enable/$port.
Keywords: Congestion control, ROCE_CC_PRIO
Detected in version: 28.45.1020
4063662Description: The 1pps Timing Error (TE) in Noise Generation (Class B) shows a constant offset when RS-FEC is disabled in the mlxlink option.
Workaround: N/A
Keywords: PTP, 1PPS
Detected in version: 28.45.1020
4303583Description: The query_header_modify_pattern command may produce inaccurate results when specific fields are used.
Workaround: N/A
Keywords: query_header_modify_pattern command
Detected in version: 28.45.1020
3875417Description: For systems that support a large number of VFs (200 or more) and can open over a million QPs, the FLR may take about 1 second per function resulting in a driver timeout.
Workaround: N/A
Keywords: VFs, QPs, FLR
Detected in version: 28.44.1204
4193036Description: The initial allocation of DPA_THREAD on group affinity allocates memory for all EUs, including stack, core dump, and other resources.
Workaround: N/A
Keywords: DPA
Detected in version: 28.44.1204
4030457Description: This release does not support InfiniBand (IB) over Windows OS when using ConnectX-7 MCX75310AAS-NEAT and MCX75310AAC-NEAT OPNs.
Workaround: N/A
Keywords: InfiniBand, Windows
Detected in version: 28.42.1000
-Description: Downgrading the following adapter cards (MCX713104AS-ADAT & MCX713104AC-ADAT) to a lower version than 20.39.2048 is not supported.
Workaround: N/A
Keywords: Downgrade
Discovered in Version: 28.40.1000
3728450Description: SW_RESET with a pending image is currently not supported.
Workaround: N/A
Keywords: SW_RESET
Discovered in Version: 28.40.1000
3614362Description: When connected to a Spectrum-1 switch system using NRZ 25G optic module supporting DME in NO FEC, an EFF BER of -13 may be seen once in 200 toggles.
Workaround: To raise the link, re-toggle the port.
Keywords: Spectrum-1, NRZ, BER, port toggling
Discovered in Version: 28.39.1002
3629216Description: mlxfwreset level 3 command is not supported for MCX750500B-0D00 / MCX750500B-0D0K / MCX755206AS-NEAT-N P/N.

Workaround:

  1. Enable mlxfwreset level 4.

    mlxfwreset -d <dev> r -l 4 -y

  2. Reboot the server.
Keywords: mlxfwreset level 3
Discovered in Version: 28.39.1002
-

Description: The I2C clock fall time is lower than the 12ns minimum defined in the I2C-bus specification.

For further information, refer to the I²C-bus Specification, Version 7.0, October 2021, https://www.i2c-bus.org/.

Workaround: N/A
Keywords: I2C clock
Discovered in Version: 28.39.1002
3179534Description: 25G/lane speeds are not supported on 200GbE optic cables.
Workaround: N/A
Keywords: Cables, 200GbE
Discovered in Version: 28.39.1002
3435259Description: The host enables the device to populate only 1 bus. When opening extra 2 Physical ports, moving from dual-port to quad-port, the user can open 2 less Virtual Functions.
Workaround: N/A
Keywords: VF, dual-port, quad-port
Discovered in Version: 28.39.1002
3525865Description: Unexpected system behavior might be observed if the driver is loaded while reset is in progress.
Workaround: N/A
Keywords: Sync 1 reset, firmware reset
Discovered in Version: 28.39.1002
3363753Description: The link is down when connected to the MMS1V00-WM (DR4) optical module.
Workaround: N/A
Keywords: 400G, link down
Discovered in Version: 28.38.1002
3439438Description: When connecting to a High Speed Traffic Generator in 400G speed, the linkup time may takes up to 3 minutes.
Workaround: N/A
Keywords: 400G, linkup time
Discovered in Version: 28.38.1002
-Description: When upgrading from firmware v28.35.2000 to a newer one, the default port speeds of adapter cards MCX755106AS-HEAT/ MCX755106AC-HEAT will change from InfiniBand to Ethernet.
Workaround: To change it back to InfiniBand, please follow the instructions in the ConnectX-7 hardware User Manual.
Keywords: Firmware upgrade, port type, MCX755106AS-HEAT/ MCX755106AC-HEAT
Discovered in Version: 28.37.1014
3376224Description: FEC override is not supported when working with NRZ speeds on PAM4 Optical modules.
Workaround: N/A
Keywords: FEC override, NRZ, PAM4
Discovered in Version: 28.37.1014
3262845Description: In the ConnectX-7 adapter card with P/N MCX750500B-0D0K, t he "Fatal Error Reporting Enable" bit controls both the fatal and the non-fatal ERR MSG forwarding. The "Non-Fatal Error Reporting Enable" bit does not affect the ERR MSG forwarding.
Workaround: N/A
Keywords: Fatal Error Reporting Enable" bit, PCIe, MCX750500B-0D0K
Discovered in Version: 28.36.1010
3329109Description: MFS1S50-H003E cable supports only HDR rate when used as a split cable.
Workaround: N/A
Keywords: HDR, split cable, MFS1S50-H003E
Discovered in Version: 28.36.1010
2844036Description: When using the "Dual Write" feature with QP buffer bigger than the maximum outstanding WQEs (128), the data being sent on the standby QP can be corrupted.
Workaround: Limit the QP buffer size when using "Dual Write" up to 128 WQEs.
Keywords: Dual-write, QP
Discovered in Version: 28.36.1010
3178339Description: PCIe PML1 is disabled.
Workaround: N/A
Keywords: PCIe PML1
Discovered in Version: 28.35.1012
3033910Description: BAR misses caused by a memory write/read actions are not reported in the AER and the device status.
Workaround: N/A
Keywords: BAR miss, AER
Discovered in Version: 28.34.4000
3140645Description: 3rd party servers may hang after warm reboot due to the PCIe switch.
Workaround: N/A
Keywords: PCIe, 3rd party servers
Discovered in Version: 28.34.4000
-Description: Changing dynamic PCIe link width is not supported.
Workaround: N/A
Keywords: PCIe
Discovered in Version: 28.34.1002
3141072Description: The "max_shaper_rate" configuration query via QEEC mlxreg returns a value translated to hardware granularity.
Workaround: N/A
Keywords: RX Rate-Limiter, Multi-host
Discovered in Version: 28.34.1002
2870970

Description: GTP encapsulation (flex parser profile 3) is limited to the NIC domain.

Encapsulating in the FDB domain will render a 0-size length in GTP header.

Workaround: N/A
Keywords: GTP encapsulation
Discovered in Version: 28.34.1002
3081264Description: 10G/40G speeds are not supported on MFS1S00-XXXX modules (200G optics) in ConnectX-7 adapter cards.
Workaround: N/A
Keywords: Optical cables
Discovered in Version: 28.33.4030
3070590Description: PLL modules are not supported in ConnectX-7 ethernet adapter cards.
Workaround: N/A
Keywords: PLL
Discovered in Version: 28.33.4030
3070409Description: When connecting a ConnectX-7 adapter card to a ConnectX-6 Dx or an NVIDIA Spectrum-3 switch, NRZ speeds are not raised when using 200GbE optical cable.
Workaround: Configure PHY_FEC_OVERRIDE on the ConnectX-7 side for the requested speed.
Keywords: Optical cables, NRZ, ConnectX-6 Dx, NVIDIA Spectrum-3, 200GbE optical cable
Discovered in Version: 28.33.4030
-

Description: Upgrading to firmware 28.33.2028 from any previous Engineering Sample (earlier than version 28.98.2406) must be done before installing WinOF-2 v2.90 driver and requires going through the following steps:

  1. Upgrade to 28.98.2406 version while the driver is disabled.
  2. Upgrade to firmware version 28.33.2028 (the driver can be enable at this stage).
Workaround: N/A
Keywords: Firmware upgrade
Discovered in Version: 28.33.2028
-Description: Downgrading from firmware 28.33.2028 to any previous Engineering Sample firmware is not supported.
Workaround: N/A
Keywords: Firmware downgrade
Discovered in Version: 28.33.2028
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