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 CUDAEnabled GPUs http://www.mathworks.com/discovery/matlabgpu.html 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. 

