One thing you can do is stop exporting channels from info1 onto grid1. This export is causing grid1 to cook every frame which seems to take 3-5ms on my computer.
The other thing that it killing it here is that the Delete, Facet and Primitive SOPs are filtering a part of the SOP chain that is cooking every frame, so they also cook every frame as well. If you can delete earlier in your SOP chain where SOPs aren’t cooking, like right after grid1, then the Delete SOP won’t cook every frame as well. Generally SOPs are very hard on the CPU when animating dense geometry. You want keep them from cooking whenever possible. I don’t know what you are attempting with these SOPs however, so I don’t know if it is feasible to move them for your setup.
A GLSL shader should be much faster, though harder to setup.
Another tip, don’t use a Material SOP, generally much better to apply the Material at the Geometry COMP level on the Render page of parameters.