I'm going to be getting another PSU shortly, this was just one to get me started.
I do think this PSU has another rail though. as I was able to get both of the blades running on this psu without underclocking the freq.
Or maybe it can just actually handle what it's rated at. who knows.
http://imgur.com/CdWMyQIJust check if any of the connectors, at any stages, including the adapter runs hot. If not you're good to go even though its a crap PSU, it should be able to handle the 400W~ DC load.