The screenshot above shows a layer of 0.1 degree cell densities representing data from Australian National Herbarium rendered using GeoServer layered on top of the Google satellite base layer, all pulled together using OpenLayers.
The performance improvement with Google maps was immediately obvious. Using the Firefox YSlow plugin we see:
|OpenLayers||Google Maps API|
So the performance difference between Google Maps and OpenLayers could be accounted for by any combination of the following:
- Incorrect use of the API (test for OpenLayers is here) and we are missing configuration to reduce tile loading in openlayers
- The tile loading algorithm for Google maps is more efficient in only loading the required tiles for selected view areas
- Openlayers is preloading more images to speed up panning. This would be good, but OpenLayers doesnt seem to prioritise the loading of currently viewed tiles.