GPGPU was definitely part of the success of recent years, but there was also a lot of experimentation and hard work carried out e.g. on CNN designs. Lots of tri

GPGPU was definitely part of the success of recent years, but there was also a lot of experimentation and hard work carried out e.g. on CNN designs. Lots of trial and error. That took a lot of time. There have been fundamental changes in the structure and training of NNs that have helped bring the step-change in success.