Looks like I cannot mine without more RAM too, this change is quite dramatic.
Though I'm close, I'm using 4 different TC's for each card, my setup will be of no use to anyone for 290x, or perhaps one of the 4 might help 1 of 4 people... who knows.
Ye many miners may have to increase system RAM, hoping I can squeeze by with 8GB and 3 GPU; gonna be close if so.