Diamond file speed of metal removal

I have very limited experience using diamond blocks to sharpen drills. I know they tend to be fine grit. Does a diamond file remove metal any faster, fewer strokes, then a HSS file of the same grit/tooth count. Or is it just the diamond can bite into hard metal while a file skates over and does nothing.
Practically if it takes say 10 strokes to sharpen a drill with a file will the diamond take the same ten or less? Assuming the metal is soft enough for the file to work does diamond offer...

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