I tried to find out which one of those two enchantments is the better one and tested them therefore on coal and iron ore (I also made some figures, because that is for some reason my idea of fun ). I am writing this thread as it might be interesting for everyone else who is looking to get the most out of their ores. The first figure shows the results for coal ore tested with Fortune V and the CEs. These results should be similar for diamond ore and to a certain extend to redstone and lapis. Surprisingly, Furnace I has a much higher impact on the drop rates than Autosmelt (AS) does, while adding both CEs didn't have any additional effect. As expected, a high fortune level further enhances the coal yield. The next figure shows the result for iron ore which should be similar to gold ore. Compared to the previous figure, Autosmelt II now has the largest impact. Unexpectedly, both CEs scale with fortune now, which does not happen in the vanilla game or with mcmmo flux mining. Since the effect of AS II compared to Furnace is not significantly greater on iron ore and worse on coal ore, I recommend to use Furnace, as AS additionally only converts 50 % of iron/gold ore (the rest has to be placed and mined again). Note: For the experience I placed the ores manually (previously mined) to eleminate any influence of MCMMO.