Q: During the Fan Festival in Las Vegas, there was an announcement regarding inventory slot expansion, but we would like to know which inventory (Inventory/Armoury Chest) is being increased and by how much!
A: We often see comments that the Armoury Chest and Inventory could not be expanded due to PlayStation®3 memory limitations, but that is incorrect. The biggest issue that prevents us from simply adding more inventory space is the amount of network usage that would occur from it. All item data is being moved along with a character when they change areas or queue into an instance, so if we were to add additional item slots without careful consideration, the amount of data being transferred could skyrocket network usage, and servers could go down very often.
Recently Inventory/Armoury Chest expansion has become possible, thanks to factors such as server upgrades, relocation of the NA data centers, and various other increases in efficiency.
Keeping stability in mind, we will be implementing this expansion in two parts. We will implement the first expansion in Patch 4.0, and will add the second expansion after confirming server stability.
The Armoury Chest will receive 10 extra slots for each category of equipment, while the item inventory will be increased by 40 slots.
http://forum.square-enix.com/ffxiv/...XXXV-Digest-(5-18-2017)?p=4145200#post4145200