Alright so here's the lowdown. At the settings I'm running here is what it looks like at the wall:

rig with 1GPU @ full load = 320W
rig with 2GPU @ full load = 623W
rig with 3GPU @ full load = 914W
rig with 4GPU @ full load = 1200W
rig with 5GPU @ full load = 1525W

623-320 = 303W
914-623 = 291W
1200-914 = 286W
1525-1200 = 325W

So it's fair to say that my cards are drawing about ~300W per card...which is more than I anticipated!

Based on what you guys have said, my dual HX820 Gold+ PSU's are 87% efficient at full load.

So taking the wall reading: 1525W*0.87= 1327Watts

Does this mean that the rig is pulling 1327W TOTAL then?