Hello Xylitol
There is nothing known as a perfect speed. Further you should not be concentrating on flipping the pages as fast as you can. This, IMHO, will make the process less effective for you.
Remember the whole intent is to be in accelerative learning state and staying relaxed while Photoreading. You should be concentrating on rhythm and not on flipping pages as fast as you can. Rhythm is something that will keep you relaxed. Paul also mentions in "PhotoReading" book
Quote:
Turn the pages of the book in steady rhythm - one page every second or two.
This should be your guiding principle while PhotoReading
The same also holds true for electronic documents. My suggestion is try Photoreading at a rate of one page every second or two, while maintaining an accelerative learning state and staying relax. Then notice your feelings and see if you have any different results. But, definitely don't focus on speed rather focus on relaxing and accelerative learning state.
I hope I have been of some help to you.
God bless you.
Kind regards
Vaibhav Sharma