Typically, day one updates for some titles are only around 12GB, but the upcoming Call of Duty: Black Ops 4 will more than quadruple that number with a massive 50GB day one update. Activision says that "for an optimized download experience", players will need at least 112GB of free space on their hard drives. That's not really a problem - and is now considered normal for most games, especially those with a multiplayer component. It can be tempting to simply issue a big launch day patch instead of delaying the release to be sure that everyone can start playing right away. Blackout can be played as soon as update installation/download reaches 30% on either PS4, or Xbox One.
The update seems to be adding necessary components for the multiplayer modes, including Zombies, Specialist Headquarters, and the new Battle Royale mode Blackout.
The update process and sized don't differ at all between the PlayStation 4 and Xbox One with identical information being shared on Activision's site for both consoles. It simply says that the day-one version of Black Ops 4 will be roughly 55GB in size with the game and all its various game modes playable after it's been completely downloaded. If you've pre-ordered the digital version of the game then you'll be all set to go as the game will go live with the patch already included. The patch itself will be approximately 50 GB.
South African retailers will be dishing out copies early so players can get the patch downloaded.
Before playing for the first time, players will need to download and install a day one update for Call of Duty: Black Ops 4.