I've discovered a few things about reading speed in my experience.
1) When I read fiction by good authors, I take great delight in reading their sentences, so I slow down drastically to take every word and piece of punctuation in.
2) Reading speed improves with practice.
3) Read smarter: if you don't need 100% comprehension then read topic sentences of paragraphs carefully then skim the rest of the paragraph for details you think are useful. And in news stories, they follow the "inverted pyramid" for paragraphs meaning that they're ordered such that the first paragraph is the most important, second one is second most important, etc. So you can stop reading at any time.
4) Choose a column width that suits you. A lot of time is spent on line transitions. Smaller columns makes this easier which you can control via your window size.