perfSONAR User Q&A and Other Discussion

[Joseph Ghobrial <>]

Hi everyone, I've reached out to my vendor but thought to ask here in case anyone has seen this.

The question is based on the below ouput the Mellanox ConnectX-4 card and slot are capable of x16, but negotiated to x8 why is that? I've looked in the BIOS and didn't find anything obvious to change it.

root ~: lspci -s 04:00.0 -vvv | grep -E 'Lnk(Cap|Sta):'
LnkCap: Port #0, Speed 8GT/s, Width x16, ASPM not supported, Exit Latency L0s unlimited, L1 unlimited
LnkSta: Speed 8GT/s, Width x8, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt-

root ~: dmidecode -t slot
# dmidecode 3.0
Getting SMBIOS data from sysfs.
SMBIOS 2.8 present.

Handle 0x0900, DMI type 9, 17 bytes
System Slot Information
Designation: PCIe Slot 1
Type: x16 PCI Express 3
Current Usage: In Use
Length: Long
ID: 1
Characteristics:
3.3 V is provided
PME signal is supported
Bus Address: 0000:04:00.0

Handle 0x0901, DMI type 9, 17 bytes
System Slot Information
Designation: PCIe Slot 2
Type: x16 PCI Express 3
Current Usage: Available
Length: Long
ID: 2
Characteristics:
3.3 V is provided
PME signal is supported

Thanks,

Joseph

--
Joseph Ghobrial
Systems Analyst II
Office of Information Technology
Rice University

jghobrial @ rice.edu

x5190