PowerVault ME4 : One of the internal PCIe buses is degraded. The hardware bus is unable to use optimal speeds.
Summary: When one of the internal PCIe buses is degraded. The hardware bus is unable to use optimal speeds. (bus: 5, actual speed: Gen1, expected speed: Gen2). This warning message may be observed on PowerVault ME4 series controllers prior to release G280R004-01. Upgrade the ME4 controller firmware to the latest. ...
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Symptoms
In ME4 recently observed arrays reporting one of the PCIe buses that have downshifted to a lower speed. This is reflected as an event 565 in the array event logs:
A815 2019-02-09 07:40:43 565 WARNING One of the internal PCIe buses is degraded. The hardware bus is unable to use optimal speeds. (bus: 5, actual speed: Gen1, expected speed: Gen2)
A816 2019-02-09 08:00:48 565 WARNING One of the internal PCIe buses is degraded. The hardware bus is unable to use optimal speeds. (bus: 5, actual speed: Gen1, expected speed: Gen2)
A865 2019-02-09 23:44:32 565 WARNING One of the internal PCIe buses is degraded. The hardware bus is unable to use optimal speeds. (bus: 5, actual speed: Gen1, expected speed: Gen2)
A866 2019-02-10 00:04:37 565 WARNING One of the internal PCIe buses is degraded. The hardware bus is unable to use optimal speeds. (bus: 5, actual speed: Gen1, expected speed: Gen2)
Cause
The PCIE bus speed degraded situation should not have an impact on the Host I/O performance, this is the internal bus for communication between the two controller modules and would not impact the data path.
Resolution
This was resolved in controller firmware G280R004-01 and above.
Upgrade to the latest available controller firmware. For more information about applying controller firmware updates see PowerVault ME4: A controller firmware update is available for your system
Affected Products
Dell EMC PowerVault ME4012, Dell EMC PowerVault ME4024, Dell EMC PowerVault ME4084, Dell EMC PowerVault ME412 Expansion, Dell EMC PowerVault ME424 ExpansionArticle Properties
Article Number: 000131303
Article Type: Solution
Last Modified: 22 May 2026
Version: 5
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