If you are using version 10.6.6 or 10.6.7 and running snow leopard. There is no need to degraf your hard drive but if you want you can also do so. It won't harm your mac. Why do you want to improve your mac performance. Is it in terms of speed if that is the cae you can just use a cleaning software to clean up unwanted file or upgrade your ram.
I had already removed those applications which I do not need. I have also removed my cache, language files and many binary files using a Mac speed up tool. It also deleted all my duplicate files to create more free space on my Mac drive.
Good to hear your problem is solve. Next time do not reformat in order to free out memory you can use mac scan to delete unwanted files but it causedba lot of money. To buy it maybe more than $59. If you have any other problem. You can come back to daniweb. Bye