This is the Settings Overview for GD > Settings > Marker Cluster page that deals with the customization of options for Marker Cluster extension.

You need to have the Marker Cluster extension installed and activated to access these settings.

General Settings

Cluster Type – You can choose the type of clustering you wish to use. For smaller sites, Client-Side is faster and more efficient. For larger sites and directories, you should opt for Server-Side.
Grid Size – This is where you can specify the grid size of the cluster in pixels. By default, the value is set to 60. If you prefer the algorithm to run faster, you can increase this value.
Max Zoom – You can specify the max zoom level monitored by a marker cluster. The default value is 15, and when this value is exceeded or reached, all markers are shown without cluster.

Settings Overview for GD > Settings > Marker Cluster