It is worth noting that "saturation" can only apply to a cluster of two or more CMGs, since it means that their rotor spins have become parallel. It is meaningless to say that a single constant-speed CMG can become saturated; in a sense it is "permanently saturated" in whatever direction the rotor happens to be pointing. This contrasts with a single reaction wheel, which can absorb more and more angular momentum along its fixed axis by spinning faster, until it reaches saturation at its maximum design speed.