it's not a great PSU, i would avoid raidmaxx PSU as they are not known to be reliable. I doubt that unit can even peak at 630w, much less continuously provide that power. It actually has a single 12v rail (as most PSU do) that has been split (its common). The PSU does not state the power provided by the 12v but I doubt it is above 40a or that the PSU can even provide that power. Here are some budget PSU i would look at if you want to upgrade (i would if I was you).
$65 out the door plus an MIR, its modularhttp://www.newegg.com/Product/Product.aspx?Item=N82E16817341017&Tpk=ocz%20600
$65 good power, bronze efficiency, good platform (seasonic)http://www.newegg.com/Product/Product.aspx?Item=N82E16817371048
$69 plus MIR, good power, solid platformhttp://www.newegg.com/Product/Product.aspx?Item=N82E16817139028
basically identical to the modstream above but with a red fan, for the same price & MIRhttp://www.newegg.com/Product/Product.aspx?Item=N82E16817341022
$70, not as much power as some others but will do the job and is modularhttp://www.newegg.com/Product/Product.aspx?Item=N82E16817182131
from the above PSU, I would go with the antec 620w, its a great price and plenty of power. The modstream would be my pick if you want a modular unit.