It is always advisable to use thelatest CUDA driver (NVIDIA ensure backwards-compatibility for CUDA drivers which mean that newer drivers are intended to work completely correctly with older applications)
The CUDA toolkit provides support forcompiling CUDA sources
Most users don't actually need to install the CUDA toolkit
The CUDA toolkit is needed only for compiling CUDA sources (e.g. for use withmexcuda orCUDAKernel)
If you do install the CUDA toolkit, ensure that the version matches the version used by MATLAB. The version used by MATLAB is described in the Parallel Computing Toolboxrelease notes
If after installing the latest CUDA driver, MATLAB cannot recognise the GPU device, then contact MathWorks support who are able to take you through additional debugging steps.