If an effect is not faster to render on the GPU than on the CPU, you lose performance time while copying the frames back and forth. This is an opportunity to point out that in a mixed CPU and GPU rendering environment, there is a performance cost to moving frames between CPU and GPU memory. But rendering motion blur on the GPU requires it to be aware of the transforms and quality, so these calculations are done on the GPU when motion blur requires it. Layer transforms and layer quality require layer motion blur to be enabled because by themselves, they do not render significantly faster on the GPU.Also, some of them are useful on non-VR footage because they are wholly new to After Effects, like VR Chromatic Aberrations.
Their advantage for VR over other effects is that they are seamless, and they wrap the ends of the VR image together. We recommend a GPU with high VRAM, 4GB or better, to use these effects. Unlike the other effects, they do not currently have a CPU fallback. A couple of technical points worth noting about the above list:
