A scheme is provided for dynamically adjusting an amount of power drawn from individual power sources to optimize the power usage without violating power limits. Coarse adjustment is provided through dynamic phase reallocation while a fine adjustment is provided through dynamic current steering. By adding a control loop around current steering techniques in digital voltage regulator controllers, power drawn from multiple input rails is balanced. The apparatus allows users to maximize the power delivered to discrete graphics cards without violating PCIe specifications. This allows maximum performance with minimal bill-of-material (BOM) cost.