In various posts, articles, etc I am led to believe(but can't find anything definitive)  that plugging your power supplies into 208/240 circuit results in a more efficient power supply and better hash rate(albeit marginal as best I can infer).   The efficiency I can believe, but I am not sold on better hash rate.

Is this true?   Should I invest in the 240V surge protector and cable(s)?  Just curious...

Setup:  I have two EVGA Super Nova G2 gold PSUs running an Avalon miner - both support 240 - and I have a 240 outlet right beside it.