If you are on CRM 2015 Update 0.1 or later, you can enable full text search and make the quick search in CRM perform faster. If you do this, there is one drawback of which you should be aware: you will not be able to modify the field length of any field set to be a find field after full text search is enabled.
If you find yourself needing to change the length of a find field, you can disable full text search; however, you will need to wait until the maintenance job runs before you can modify the field length. This can take a while.
Alternatively, some administrators have reported success by manually dropping the full text index using SQL Management Studio, changing the field length in CRM, and then manually recreating the full text index in SQL. This approach is unsupported.