Are your’e PCIe card running at full speed ?

Are youre PCIe card running at full speed?

Its pretty simple to check if you are running Linux. Just at a command prompt type

# lspci -vv

The command will return a list of PCI-Express devices along with the supported and actual speed/width.

Any difference in the supported and actual speed (or width) should trigger consideration whether or not to reconfigure the HBA layout.

This HBA run isn’t properly configured, the current PCIe slot has a width of 4 but the card actual REQUIRE a x8 slot :

4c:00.0 Ethernet controller: NetXen 10G Ethernet PCI Express (rev 25)
Link: Supported Speed 2.5Gb/s, Width x8, ASPM L0s, Port 0
Link: Latency L0s <64ns, L1 <1us
Link: ASPM Disabled RCB 64 bytes CommClk- ExtSynch-
Link: Speed 2.5Gb/s, Width x4

Sample of a HBA running as intended :

4f:00.1 Fibre Channel: QLogic Corp. ISP2432-based 4Gb Fibre Channel to PCI Express
Link: Supported Speed 2.5Gb/s, Width x4, ASPM L0s, Port 0
Link: Latency L0s <4us, L1 unlimited
Link: ASPM Disabled RCB 64 bytes CommClk- ExtSynch+
Link: Speed 2.5Gb/s, Width x4
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