3d texture and PC

my graphic care is nvidia geforce fx 5200 and i use opengl extentions to do a 3d texture example,but it seems very slowly. i just want to ask does my pc can support the 3d texture(161616)
thank you!

GeForce FX support 3D textures in hardware.
What are your texture internal format, parameters and environment settings? (post the code)
What means “very slow” for you?
What do you render with it? (fillrate limited?)