Can't create 3D texture size more than 2G

Hi there,

I am using Tesla C1060 and the latest driver The card has 4G vram. My opengl volume renderer can’t allocate more than 2G 3D texture, e.g. when I set texture size(2048, 2048, 512), with internal format GL_ALPHA8. It give a out-of-memory error. If I set the texture to be a bit smaller than 2G such as (2048, 2048, 500) it works. Is there a 2G vram access limit per process?

Thanks for any help!