There is a 3rd party fix that might be applicable to you and your situation and I found it while just browsing the apple store a couple of years ago.
Alsoft Disk Warrior
This software does to mac what disk defragmentation does to PC. We forget sometime that at the end of the day a Mac is a computer that needs to be cleaned up at times. If you are an editor, and graphics designer, photographer or audio person, we often delete and import a lot of files and forget that that causes out system (Mac or PC) to have gaps in the operating system which causes it to slow down tremendously. If you follow the instruction on the disk of Disk Warrior, this should help you quite a bit. Wish you the best
Semper Fi
Andrew Johnson
Director/Videographer
770-866-5457 – Mobile
404-462-3207 – Office
number1videoman@yahoo.com
“What We Do In Life Will Echo In Eternity”
Semper Fi
Andrew Johnson