thx a lot.
So this means, I can't calibrate the gyro manually only automatically, or thermal calibrate the cc3d?
And if I have a drift - how can I compensate them?
Gyro is calibrated (biases calculated), just no thermal correction, it's not really needed on racing copter.
Gyro is most accurate sensor but due to it's physical properties it drifts a bit no matter what you do (it's property), that's why accelerometers are used which are less accurate but do not drift.
In rate mode, just Gyro is used, and in attitude mode Gyro+Accel. You will always have a little bit of drift even with two sensors, but they are calibrated when you press that button.
You can try adjusting board rotation by 1deg here and there if it drifts in one direction or another.
Like f5soh already mentioned.