Tile engine problem!!

Hello everyone: I am developing a game with 2d background and 3d characters running on it. I decided to use a tile engine for the 2d part. However, when testing the program, rendering a 10*10 tile constituted map seems to be intolerably slow while rendering a 4*4 one is completely normal. I only rendered one layer, and used only one texture which is split into 4 parts. Is my situation a common case for tile engine? Are they slow for rendering? Is there anyway to remedy this? Thanks for any advice in advance Ji