I came across a number of Directory Access Services that I as an average user do not use. Disabling them, along with disabling network ports not used (in System Preferences -> Network -> Network Port Configurations), has given me a noticable speed improvement. From my experience with Linux, I imagine there are a number of services that many people don't use. Turning off more might yield UI speed improvements like those of Linux counterparts.
To disable extraneous services, launch Directory Access (in /Applications -> Utilities) and click the lock to make changes (enter your password when prompted). For information about what each service does, select Directory Access Help from the Help menu. When Help opens, click "Tell Me More" and then select "What are Directory Services" and "Configuring Open Service Directory Protocols." As an example, here's a bit of the output from the second selection:
Open Directory uses many protocols to access administrative data in directory domains and discover services on the network. You can enable or disable each of the protocols individually by using the Directory Access application. The protocols include:After reading this, I turned off all of them as I am at home and not on a network. I have noticed improved use of memory and no problems. Note: I did notice some information I'm not sure about in /var -> log -> system that is too long to mention here.[trimmed...]
- AppleTalk, the legacy Mac OS protocol for file and print services. AppleTalk is configured automatically.
- BSD Configuration Files, the original method still used by some organizations for accessing administrative data on UNIX computers.
If you disable a protocol on a computer, Open Directory does not use it for directory access or service discovery on the computer. Other network services may still use the protocol, however. For example, if you disable the AppleTalk protocol, OpenDirectory does not use it to discover file servers, but you can still connect to an AppleTalk file server if you know its URL.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20030605072807412