As the training progresses and more simulation data is cached, a point is reached where there is a sufficient amount of cached data to accurately begin estimated a number of physical properties using reweighting. Although it was observed that reweighting was able to estimate the physical properties faster (on average roughly 5 minutes per property) than by direct simulation (on average roughly 25 minutes per property) the overhead (green bars in Figure ) associated with attempting to reweight when there is not enough cached simulation data to yield an accurate estimate of a data point (less the 50 effective samples) is somewhat large. In these cases a new simulation must be performed instead in addition to the failed attempt at reweighting. There is currently no way to detect whether there will be a sufficient amount of cached data to reweight until reweighting has actually been attempted, and hence this overhead will always be present.