[dba-SQLServer] Performance of a unique index

Are there any performance implications for a unique index, pro or con?  I
have tables where no data is added after the tables are set up.  Are unique
indexes faster than non-unique?  Are they slower?  No difference?  I do not
need the capability to enforce uniqueness since the tables are completely
static so I want the fastest index.

John W. Colby
Colby Consulting
www.ColbyConsulting.com