A few years back, I performed a few calculations of metallic slabs using VASP and the Atomic Simulation Environment (ASE). I'm by no means an expert, but I noticed that the calculations were very CPU intensive e.g. ~24 cpu-hours (in parallel) to get a single energy point and gradient calculation. 

Considering the size of the system this makes sense, however, I'm wondering, have graphics processing units (GPUs) changed this scenario much? Is the use of GPUs becoming more popular in plane-wave DFT?