map becomes slow on android device while zoom in out and drag.

Question

Respected All, I have use google map in my application. On that map i have added more near about 100 overlays() to show different locations. When i install my application on device the maps seem very unresponsive/slow. Is there some reason for that? If any one know cause of it, please help me.

                                                                       Thank You
                                                                        Vikram