make sure all your mb/sound and network drivers are up to date. also check to see what running in the background. things like apple update can be turned off to save memory. i would also run ccleaner and run malware scan and see if your anti virus is out of date or expired. malware and some virus can use a lot of your network bandwith. also if your running wifi check that no one leaching.
Even when i run the game on the lowest resolution, I still have the same issue. Im getting 20-30 FPS while im by myself, but it can drop to as low as 3-5 FPS when im intertacting with other player or NPC graphics.
And I seem only to get a slight game performance increase when I go from high to low graphics settings
The Phenom 9500 runs at 2.2 GHz which is at the very low end of the system Minimum req. Most MMOs in the first place struggle when running with AMD CPUs. More then likely it is your CPU causing the problems. Look at the SWTOR support forums. SOOO many of the problems are with AMD rigs. EA really optimized the game for Intel / Nvidia.