Storing entity pointers in a vector wouldn't help anything since now instead of loading memory of the entity you're loading memory of a vector of pointers and still the memory of the entity.

As it is now each node in the list is the entity itself. You load the node you've loaded the entity and ...

I was also surprised to see use of a linked list. The problem I see is not that the data for each entity needs to be loaded, but that the out of order execution cannot load ahead because it doesn't know the address of the next entity until the current one has loaded. Additionally, modern CPUs ...