X-3 has 3 large fans cooling 10 minions, seems like X-1 needs at least a small fan or heatsink is the only thing cooling it down?
X3 seems to have 6 fans. Either way, you are going to need active cooling.
X3 looks nice btw, one of the first bitcoin asic system designs that appears to make total sense (from cooling perspective).
And the fact they are underclocking their chips to achieve their promised power efficiency also implies that these machines should be able to overclock by 50%, provided you can supply the required power and keep them cool.