CPU faster then GPU in cycles?

When I use CUDA for rendering I get actually longer render times compared to the CPU rendering. My computer is a laptop with i7-3610QM (4 cores, 3GHz, HD 4000 graphics) and an nvidia geforce GT 640M (384 CUDA cores). I know that the GPU isn’t the best and greatest around but I still though that it would beat CPU rendering or is i7 in this case superior, or could it have to do with driver problems or something, it is the latest but from the PC manufacturer not nvidia. The scene i tried was just some boxes/spheres and one light with very basic diffuse material in the latest blender (2.64a) on windows 7/8, will try on linux if I ever get cuda installed. Any input/opinions are greatly appreciated, or is it simply expected with such a GPU?..

The average mobile graphic cards are pretty low end… I wouldn’t be surprised if your CPU was faster.

typical speedup is around 4-8x, but it very depend in scene. Some pictures will be good ( IIRC you can not insert pictures until 10 posts on forum becouse of anti spam feature, but you can use pasteall.org and insert link here )
Did not notice it is mobile variant, of course it have modification to cut any computational features to usual game and 2d related tasks in comparison with full feature desktop card, even if CU number is equal.

640M is a very slow GPU. On top of that, the entire 6xx series has trouble with Cycles and GPGPU tasks in general. It’s entirely normal that your CPU is faster in this case.

Thanks guys for the replies. Yeah, I figured as well as the consensus seems to be from the replies that the GPU is not really up to par. I though of hearing with more knowledgeable people before going the route of hunting down drivers different builds and all the rest. Cheers…

what were the render times for your CPU vs GPU?

Before you give up on the GPU, did you use the default 8x8 tiles setting? Try setting 2x2, 3x3, etc and see if you get
faster render times.

I have a laptop with the same specs but GPU is overclocked and it is screaming fast compared to my quad core i7.