Rockstar Games has posted up a detailed new Q&A on the upcoming and hugely anticipated Grand Theft Auto V, which among other details, confirms that the game on both PlayStation 3 and Xbox 360 will require a mandatory 8GB installation prior to gameplay.

As the Xbox 360 version will ship on two DVD discs (in contrast to the PS3's single Blu-ray), the installation will prevent players from having to swap discs mid-game, but the size of the installation interestingly violates one of Microsoft's long-standing policies for the Xbox 360: that every game should be playable on the baseline Xbox 360 model that ships without a harddrive.

For Xbox 360, Grand Theft Auto V will ship on two discs; Disc 1 will be used for a one-time mandatory install and Disc 2 will be used to play the game. After the install, players will be able to enjoy both Grand Theft Auto V and Grand Theft Auto Online without any need to switch discs.

This initial install will require an Xbox 360 Hard Drive or an external 16GB USB flash drive with at least 8 GB of free space. If using a USB flash drive it must be at least USB 2.0 with a minimum 15mb/s read speed and formatted for Xbox 360 use. A new USB flash drive is recommended to ensure optimum performance. For PlayStation®3, the game ships on one disc and will install content as soon as you insert the game. The install is roughly 8GB, and players will be able to play as soon as the install is complete.

Of course, most serious Xbox 360 owners already have large harddrives attached to their consoles, so this won't be an issue for them. However, the baseline model Xbox 360 sold today (now sub AU$200) features only 4GB of available internal storage, and originally --back when memory card units could be used for savedgames-- the first "Core" model Xbox 360 consoles shipped without any harddrive at all.

Until now, all disc-bought games have still been playable on a baseline model Xbox 360 console --even if players weren't able to save a game, they were still able to get it running-- so it seems in the twilight years of the console, Microsoft has now conceded that long-standing requirement, at least waived it for the blockbuster behemoth that is Grand Theft Auto V.

The Q&A also notes that we can expect the first actual gameplay trailer from GTA V soon, and reminds us that they still "don’t have anything to share about the possibility of a next-gen or a PC platform release at this time and we are completely focused on delivering the best possible experience for the consoles people have right now."

Grand Theft Auto V lands on PlayStation 3 and Xbox 360 September 17th 2013.