  In this technical report, we consider an approach that combines the PPO
objective and K-FAC natural gradient optimization, for which we call PPOKFAC.
We perform a range of empirical analysis on various aspects of the algorithm,
such as sample complexity, training speed, and sensitivity to batch size and
training epochs. We observe that PPOKFAC is able to outperform PPO in terms of
sample complexity and speed in a range of MuJoCo environments, while being
scalable in terms of batch size. In spite of this, it seems that adding more
epochs is not necessarily helpful for sample efficiency, and PPOKFAC seems to
be worse than its A2C counterpart, ACKTR.
