SAS3 Backplane 9341-8i Negotiation 150MB/s

[techmattr]

Supermicro SAS3 Backplane and a LSI 9341-8i are negotiating at 150MB/s instead of 600MB/s.

In the same server I have a 9200-8e connected to a Sans Digital DAS which is negotiating at 600MB/s properly.

What could be the issue with the SAS3 connection?

 

[rvassar]

Check your cables for damage. When they auto-negotiate down, they're trying to make due with what they have. Something simple, crimped foil shield, etc... What looks like an abraded cable to you, looks like the fallen Tower of Babel to the controller. Other options, bad solder joints, bad capacitor on the backplane, etc... Not familiar with SM backplanes, but... Backplane firmware up to date?