One of the features offered by Microsoft's New Xbox Experience is the option to install games to the hard drive, but Bungie says that's not really a good idea for Halo 3.
That's because installing the game to the console hard drive actually increases loading time, according to an Inside Bungie news post. While some games experience a performance boost by being read from the drive, several websites reported that Halo 3 load times could be "significantly longer" when coming off the HDD, a phenomenon confirmed by Bungie's own internal testing.
Bungie engineer Mat Noguchi said the problem occurs because Halo 3 cannot tell whether it's running from the DVD or the hard drive. The game is designed to automatically copy map data to the hard drive on Xbox 360 systems equipped with the device, a process it goes through even when the full game has been installed to the drive; the performance difference comes from the fact that while the console can read from the DVD drive while simultaneously writing to the HDD, reading and writing on the same device - in this case, the hard drive - must occur sequentially, and thus takes more time.
Even though Halo 3 is barely more than a year old, the roots of the glitch can be traced back to its age. "We shipped Halo 3 before Microsoft finalized this particular [NXE] feature," Noguchi added. "As a result, we were not able to take advantage of it (or any other potential optimizations we discovered after shipping Halo 3). Perhaps we also coded too close to the metal."
He also implied that Bungie was unlikely to attempt to patch the game in order to gain a performance boost through the NXE enhancements. "While anything is possible, it would be a significant undertaking to try and retroactively patch/update Halo 3 to be optimized to take advantage of the HDD install features of NXE," he said. "The risks of doing that and the resources required has to be carefully considered against what could really be a rather insignificant change to the player experience."