it'll run with the non-PoE supplies, it'll just disable poe (obviously) but you're not going to save any power draw or gain efficiency. the PoE supplies are two seperate DC supplies, the 12v supply that powers the actual switch is the exact same 250w capacity as the non-PoE models. There's a second DC supply around ~54v with a capacity of 750w that is strictly for the PoE daughterboard, it's not going to cause any extra power draw with no PoE devices in use. and even if you do enable a few PoE devices, you're looking at an extra draw of maybe 2 watts per PoE device, so even if the 54v DC rail is doing 50% efficiency because the draw is so far away from it's rated load, you're still barely looking at 2 extra watts of losses