I have a new laptop with a high end (GeForce GTX 770M) discrete GPU, but when I plot large amounts of data (50k+ points), it still seems quite slow and sluggish. Is Matlab using the GPU to render the graphics? If not, is there a way I can make it use the discrete GPU instead of the onboard CPU graphics?
Check this guide:
MATLAB GPU Computing Support for NVIDIA CUDA-Enabled GPUs
It explains what you want to know.
It will not automatically use the GPU to do normal plots.
However, if you have the parallel computing toolbox and work with a
Described in this Mathworks newsletter: GPU programming in MATLAB.