Please disable SES2 function to solve the issue from LSI expander firmware backplane. You can also update the 1680 adapters and on the 188x adapters firmware to version 1.50 or later. For ARC-1680ix series, you also need to update areca expander firmware to date: 11/30/09 or later.
Tags: ARC-1680, ARC-1680ix, ARC-188X, drive, driver, firmware