We have known for some time that id Software’s Rage was going to arrive on two discs for the Xbox 360 and a single Blu-ray disc for the PlayStation 3. John Carmack let the cat out of the bag during his keynote at Quakecon that installing the game to the hard drive on the Xbox 360 yields the best play experience.

Of course, installing the game to the hard drive does normally improve performance; the only thing is that to install Rage to the hard drive on your Xbox 360 will take a lot of space. Just how much space? How about 22GB of hard drive space! Installing the two discs to the hard drive does apparently take a long time, but Carmack insists that it is worth it.

Some Xbox 360 owners are going to be complaining about the 22GB necessary for the install. It is apparently an all or nothing deal, as there is no partial install option.

One other interesting revolution during Carmack’s keynote on this topic was the confirmation that the Blu-ray drive on the PlayStation 3 was slower accessing data than the DVD drive in the Xbox 360. This isn’t that big of a discovery, as access times have been known to be slower on Blu-ray for some time.

RAGE is still slated for release on October 7th worldwide for the Xbox 360, PlayStation 3, PC, and Mac.