Infiniband Tools and Debugging
Checking Link Speeds
Run iblinkinfo as root. This will show link speeds of all ports in the network (both on switches and HCAs).
E.g. (rc14 or its switch has some issue causing it to run at 2.5Gbps QDR):
[root@rc14 ~]# iblinkinfo |grep \"rc 50 15[ ] ==( 4X