The hardware specs themselves are only one part of the performance equation. Remember how one of the first things we used to do to Windows PCs was reformat it to get rid of all the junk and bloatware to make things faster for gaming? And then someone says “Dude, WinBlows is a !@#$ing pig, if you want to get max performance out of your computer, uninstall that crappy OS and install Linux!”
You have the same thing going on with SOC and the Android OS it ships with. If you can (and Oculus can–I used to work there) throw away the reference software and instead optimize and rewrite it with extreme purpose, you can get large performance increases.