Animation.Sample cost increasing over time = losing FPS

Profiling the game see the Animation.Sample go from 8% to over 30% of the CPU usage in about 30 seconds. It continues to climb passed Camera.Render within a minute and just keeps going. This equates to the framerate dropping from over 40fps to < 20fps in a couple of minutes on the debug build.

I don't think it's a scripting issue as the same script doesn't affect performance of non-animating assets.

Attached are profile grabs of CPU and Rendering - any suggestions?




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Unity 5.6.1p4

x12 characters with 10 bones each and 5 animations.

Compute skinning on.

Quality Settings - 1 bone.

Vsynch Count - every v blank.

Animation culling type - Based on Renders.

Imports settings: Optimise mesh, high compression. Rig is Legacy, store in root. Animations set to keyframe reduction & compression.