Win 7, GeForce 970
Armature modifiers are still being calculated for hidden objects, resulting in degraded performance for animation previews of an armature driving multiple objects, even when not all modified objects are visible.
Exact steps for others to reproduce the error
With attached file, preview animation, and observe playback rate. Remove or disable armature modifiers on hidden clothing or hair items (under respective dummy holders): alternatively, delete hidden objects. Preview animation and observe playback rate again. On my system, playback rate increased from 5fps to 30fps