To expand on this: GPUs are (basically) hardware devices for doing vast numbers of matrix manipulations very very fast in parallel, with limitations on the siz

To expand on this: GPUs are (basically) hardware devices for doing vast numbers of matrix manipulations very very fast in parallel, with limitations on the size of the matrix. CPUs can do matrix manipulations, with less parallelism. Things like TressFX uses the tridiagonal matrix algorithm[1] to solve a linear system representing the hair constraints system. This could be implemented on a CPU as well, doing exactly the same thing with the same algorithm. It would run slower though! [1] https://en.wikipedia.org/wiki/Tridiagonal_matrix_algorithm https://en.wikipedia.org/wiki/Tridiagonal_matrix_algorithm [2] Slide 37, https://www.slideshare.net/DevCentralAMD/gs4147-billbilodeau https://www.slideshare.net/DevCentralAMD/gs4147-billbilodeau