I am in the midst of converting old googlemap v2 code to v3 and it looks if v3 is much slower than v2?
Most of my code change is just replacing G with google.maps. (GMarker to google.maps.Marker)
Any tips or tricks how to speed things up??
The solution might be as simple as experimenting with different versions of the v3 API by trying v=3.4 and v=3.5 in your links that load the API like so:
<script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false&v=3.5"></script>
And:
<script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false&v=3.4"></script>
On a site I built, the product manager felt that Streetview in particular was sluggish in 3.6. When I rolled it back to 3.5, he felt that it was a noticeable improvement.
Don't use it unless you really need it. Never change a running system. Maybe you want to write a better marker solution with a better clustering (spatial index, quadtree, heatmap)? I.e. Google's fusion table doesn't support a spatial index. You want to look for Nick's spatial index hilbert curve quadtree blog.
My problem probably was with using FireBug - then the V3 api is loading slower than V2. Also, switching between satellite and normal map makes slow fade effect when FireBug is on.
来源：https://stackoverflow.com/questions/6801251/googlemap-api-v3-slower-than-api-v2