tweak os x by terminal

http://www.learningosx.com/101-ways-to-tweak-os-x-using-terminal/

speed up xcode tips

here the source:)

I configured Xcode to use 3, 4 and 8 subprocesses, instead of the default 2. You can set the number of processes Xcode uses from Terminal as follows:

defaults write com.apple.Xcode PBXNumberOfParallelBuildSubtasks 4

These are the results I got (all on the 64-bit kernel):

Processes	2	3	4	8
Time	57.3 s	44.5 s	43.3 s	47.0 s

My test-case was a full build of the FolderGlance code base. I timed the build with my iPhone, so the results are not completely accurate. However, barring any measurement inaccuracies, the results were quite good:

Kernel	32-bit	64-bit
Time	57.3 s	50.2 s

Pretty good for simply switching to the 64-bit kernel! In case you are wondering: Switching to the 64-bit kernel can be done by either holding down the 6 and 4 keys while your Mac is booting, or you can execute the following command from Terminal to make the change persistent:

sudo systemsetup -setkernelbootarchitecture x86_64