As we’ve already told you, the Xbox 360 version of Grand Theft auto V will come on two discs; one to install off, and the other to play off. you might’ve thought that installing both would give you better performance – but Rockstar actually recommends not doing that.
While they’ve not made their reasons clear, they have said it’s not recommended to install both discs. One reason that could be posited is that the installed bits are already reading from the physical disk drive, and installing the other disc would force the hard drive to read, seek and write all the time, lowering performance. It’s possible that installing one disc to the HDD and installing another to a particularly fast flash drive might mitigate this.
@TurianKnight We do not recommend that.
— Rockstar Support (@RockstarSupport) September 15, 2013
— Rockstar Support (@RockstarSupport) September 16, 2013
That does, however, mean that 360 owners might have to be subjected to the sound of the jet engine disc-drives when playing.