On my NVidia NVS 510 with 3 displays the second and third (or better the first and second) display were waking up every few seconds after being suspended. First I thought it’s a driver problem, so I’ve upgraded to the latest beta drivers. But then I’ve found somewhere a suggestion, that maybe the displays are triggering an event after being suspended (they’re connected via DisplayPort). So I’ve checked the configuration of my second and third HP LP2475w display and voila! I’ve disabled Auto-Detect Input and Auto-Switch input (on the displays) and forced the default input to DisplayPort, since then my displays won’t wake up after being suspended :-) As expected. Finally!