Due to the sheer size of the game, Grand Theft Auto V will be shipping on more than one disc for Xbox 360. With 360 games there is always the option of installing the disc for better performance, but Rockstar advises against this.
In addition to the mandatory 8GB install from the get-go, why wouldn’t one want to also install the second disc to the hard drive? Apparently, textures have more trouble loading from the hard drive as opposed to from the disc. Rockstar had this to say on Twitter:
Rockstar has not officially said the reason for doing this, but it’s probably best to defer to the judgment of the game’s creators in this case.