I don't think I write all that much faster than other writers, but I do write for much longer hours. On any given day, I write for six to eight hours straight, and edit for two to four at night. I rarely give myself days off, but I will "buy" time off by writing extra the day before. These are minimums, too -- I have a couple of days every week when I work sixteen to eighteen hours, especially when I'm trying the kill a deadline.
Daylight Savings Time usually confuses my internal clock for a good week, but this morning I woke without the alarm at 5:13 a.m. My goal is to get started by 5:30 a.m. and finish an hour of writing before the kids wake up for breakfast. It's a good hour, too: I don't have to look at anyone but the screen for an hour, and I have that lovely sixty minutes to be silent, surly and chug down my tea while I write. Works well for me; today I've already written 1055 words.
If you're interested in increasing your daily output and haven't tried getting up a little earlier to write, give it a shot. You may surprise yourself and find it helps.