During Sony's live coverage from PlayStation Experience, What Remains of Edith Finch Creative Director Ian Dallas explained how the PS4 allows him not to worry about memories like he had to do while working on his previous game on PS3, The Unfinished Swan.

I think the biggest change I've noticed so far, and again, we're not close to releasing this game yet... It's 2016 so I'm sure there are a lot of things that we'll painfully learn between now and then... But we don't have to focus on memory as much.

I mean, The Unfinished Swam seems like a very small and simple game, but we probably spent 25-50% of our time especially towards the end just cutting things up so that they would fit into the memory that we had.

Scenes when you grow the vines, and you look back, those were just powerful moments in the game where people looked back and saw this landscape that had been very confusing to them in the beginning of the game, but then they reach a point where it becomes a hold up, but that's also something that you've created and that you have a natural affinity for... So there are powerful moments that we really wanted to support, but in order to do that, you have to spend a lot of time just carving things up, which we no longer have to do.

Considering the fact that the PS3 had an absolutely tiny RAM on board, it's not surprising that developers had problem, nor that they strongly requested eight gigabytes for the PS4.