My reading says otherwise. So does my testing. DPI from what I'm reading is the same thing as CPI.
Short for characters per inch, a typographic measurement specifying the number of characters that can fit on a printed line one inch long. The measurement really makes sense only for fixed-pitch fonts where every character has the same width. For proportionally-spaced fonts, the cpi represents an average number rather than an absolute number.
All I'm seeing is "per inch".
Allen was saying, the mouse would track at a much smaller scale on your surface. So if your OS side pointing settings were cranked or even neutral, it would track more surface while at a software accelerated rate. This was my understanding, and ever since I had changed the settings I find the head a lot more quicker. Same with sniping, with my original settings I had to poke my mouse to actually get my reticle between their eyes. With my new settings I can actually pin point my target much faster and respond at the appropriate time.