Perhaps. What size is the image?, how many polygons does the wall section have?, is the texture repeated over the wall?
I tend to use textures at 1024x1024, or 512x512 - and things tend to be pretty quick with that, and if you could use 256x256, then it would be even quicker. For polygon counts, I like to give about 200,000 polygons on screen at once maximum, not considering normal maps. If an object uses a shader, for normal mapping mainly, then it has to be really lean - maybe try and use cubes wherever and whenever you can.
Health, Ammo, and bacon and eggs!
