LARGE 32 BYTE FLOAT TEXTURE DISPLAY

Hi all, I start with openGl and shader, any help is very useful for me Here is my problem: I'm trying to write software to display a big floating point textures (RGB image 32 float). I am using : glTexImage2D(GL_TEXTURE_RECTANGLE_NV, 0, GL_FLOAT_RGB32_NV, w1, h1, 0, GL_RGB, GL_FLOAT, tableau); It work correctly but the PROBLEMEM, that when the texture is greater than 4096*4096 (data in stocked in the “tableau”), I obtain segmentation fault, I think it’s normal because I’m using nvdia 5200 card (this is the limit) … Does any body know this problem? And have a good idea to view big texture (for example 16000*16000 ) ? My question is : 1)how i can with shader tile my big image into multiple textures? if we now some code example, it is very cool ... 2)i hope for optimal method with maximum of speed... I now that it is possible to use Memory Mapping (CPU) but i'm not sure if it is possible in the case of shader+OpenGl(GPU)? Thanks a lot.