I have to say, I was pretty underwhelmed by the copper golem sorting farms in Minecraft. At first, I figured I just needed to leave my character AFK overnight to see real progress, but these golems were ridiculously slow at moving loot through the pipeline. My setup feeds two double chests into a copper chest, which should be pretty straightforward, yet the first golem took forever to decide where an item belonged. I have a row of six golems, each managing nine chests, but the lead golem spent way too much time repeatedly checking the same storage boxes before finally realizing an item needed to move to the next stage.
It got worse, too. I spotted the same item types ending up in chests farther down the line, which made it look like the golems were scanning a matching chest, ignoring it, and passing the item along anyway. It was frustrating to watch. More than once, I had to smack items out of a golem's hands and manually drop them into the next-stage chest just to keep the system from stalling.
I was about ready to scrap the entire automated setup and go back to sorting everything manually when I finally realized what was wrong. The last hopper in the chain was full and didn't have a chest available to dump items into. The attached chest couldn't send any more items into the hopper because all five hopper slots were already occupied. That prevented the golem from dropping its current item, which meant it couldn't pick up anything new. After checking the rest of the system, I found the other hoppers were backed up as well. They each had only a single copper chest to empty into, so they had become bottlenecks too.
I added a double chest at the end of the line, and now the sorting process is working properly. Yay! It took me way too long to notice.