I thought i would share some things i have tried on a few machines with the same positive result.
I just fixed all my problems with a few things.
do the following.
1- change disk pre load to 2 Seconds… try one second. after each change hit apply on each change.
2- disable the stupid auto record enable setting that creates havoc.
“Enable Record on Selected MIDI Track” found in “Preferences → Editing → Project & MixConsole”.
3- leave Asio guard on & change your buffer settings to find what works best.
4- With kontakt cores TRY OFF FIRST
Then follow the attachments.
5- Lastly I see the mac terminal hack, I have done this & man! stable as a rock! on mac
terminal Hack… more like a graphics acceleration fix. listed on the image below & taken from Fabfilter.
Windows: Click the Start button, type ‘regedit’, Enter to open the Registry Editor. (You might have to give permission to continue.) Navigate to HKEY_CURRENT_USER\Software\FabFilter. Right-click and select New > DWORD (32-bit) Value. Name it GraphicsAcceleration and ensure its value is 0.
Mac OS X: Open Terminal and type: defaults write com.fabfilter.Common GraphicsAcceleration 0
The above steps will turn off graphics acceleration for all FabFilter plug-ins.
To re-enable, reverse the effect, change the value 0 to 1 in the steps above.
I still find cubase 8 a little buggy, even on a totally new system… just proves it’s not our computers.
regardless these small fixes, really fixed up performance for me & a few friends machines as well.
enjoy 
