FWIW I'm showing just shy of 1GPM with a single D5 vario on setting 4 or 5 (I want to say that it's set to '4', but honestly I can't remember for sure which I had it set to last, and I have it mounted where the speed control knob is not easily accessible. Whatever I currently have it set to I plan on leaving it there). I monitor the flow rate with a Koolance FM19 + frequency adapter/display.
I'm running 5 blocks and 2 rads: XSPC RIVBE blocks, Raystorm CPU block, 2x XSPC Razor GPU blocks (in parallel), and a 480 XT45 & Monsta 360. It's still a work in progress so haven't gotten around to pushing it and seeing how my temps will be on overclocks, but I don't suspect that I'll have any issues related to the pump for my loop.
Edited by Unicr0nhunter - 3/19/14 at 2:35am