I am using Force.com IDE to work on multiple projects. On one of them, when I click on Save to server, it tries to deploy to server (maybe even deploy the whole project) and takes forever to save (I have not waited long enough for it to finish). I know it should take a few seconds to "save" that component to server and not minutes to "deploy" to server. My colleague can save to server on the same org and his does not initiate a "deploy". that makes me think there is a setting somewhere on Force.com IDE that automatically deploys when saving to server. Any ideas?
You can check your project settings under Projects > Properties > Force.com > Deployment Options, and make sure that "Tooling API when available" feature is checked. However, there's a limit on the number of elements that can be deployed at once using the Tooling API, and so if too many files are "dirty", it'll kick off a full deploy instead. You might need to refresh all the files in your project using the context menu (right-click) on the project, and choosing Force.com > Refresh from Server. Keep in mind that all local changes will be lost. Finally, if all else fails, try deleting the project and starting fresh. You can view your previous deployments in Setup (inside salesforce) to determine how many files were actually included in the payload, and to watch the progress of the deployment.
If the whole project is being deployed on save of a single file, that sounds like the option 'Build Automatically' is checked. Make sure the option 'Build Automatically' (Project > Build Automatically) is unchecked.
The downside however is that save/quicksave will save the file only locally. So you'll have to use context menu and use option 'Save to Server' (Force.com > Save to Server) to, well, save it to server.