Rockstar has advised Xbox 360 owners not to install Grand Theft Auto V's play disc, as it'll negatively impact performance.
The Rockstar Support twitter explains, "For optimal performance, we recommend not installing that disc. We will have more info on our Support Site at launch."
Grand Theft Auto V comes on two 8GB discs on Xbox 360; the first is a mandatory "install" disc, while the second is the "play" disc. While you'll have to install the former (as you might have guessed), the studio has warned against trying to do the same for the latter as it'll negatively impact how the game runs.
Subject: DON'T! install Grand Theft Auto V Second disk!-Xbox users only 
