Multiple compute.geometry and Console Window Host sessions taking up memories even after GH file is closed

I launched multiple “local compute instances” on Hops component, and these compute.geometry and Console Window Host sessions seem to remain there, taking up quite a lot of memories, even after I closed Grasshopper, as shown below.

Is this normal?

Anyway, adding additional local compute instance does increase the performance of the function Hops component calls significantly, as show below:

using one local compute instance:

after adding one local compute instance:

Rhino is the top-level process, not Grasshopper. Do the compute.geometry processes disappear after closing Rhino?