"... so, I thought, why not?"

The system is currently powered by two 700w Thermaltake Toughpower supplies.

I'd expected that a can (5 drives) could be supported by a single 12 volt rail (each supply has 4). However, if I fully populate 3 cans (15 drives) on one supply, it "cycles" the power, and the system won't start.

With 1400 watts available, should I really need more power?