Slow OSX booting with black screen before apple logo Every time I boot my macbook, there is always a black screen before the Apple Logo pops up. The blackscreen stays for around 15-20 seconds. How can I resolve that problem?
It can happen, if you doesn't have selected a specific start-volume.


From the Apple menu choose System Preferences.
Click the Startup Disk icon in System Preferences, or choose View > Startup Disk.
Select your startup disk from the list of available volumes.


After that, restart your mac and the blackscreen shouldn't appear before a start.