On Maxwell there are 4 register banks, but unlike on Kepler (also with 4 banks) the assignment of banks to numbers is very simple. The Maxwell assignment is just the register number modulo 4. On Kepler it is possible to arrange the 64 FFMA instructions to
eliminate all bank conflicts. On Maxwell this is no longer possible. Maxwell, however, provides something to make up for this and at the same time offers the capability to significantly reduce register bank traffic and overall chip power draw. This is the operand reuse cache. The operand reuse cache has 8 bytes of data per source operand slot. An instuction like FFMA has 3 source operand slots. Each time you issue an instruction there is a flag you can use to specify if each of the operands is going to be used again. So the next instruction that uses the same register
in the same operand slot will not have to go to the register bank to fetch its value. And with this feature you can see how a register bank conflict can be averted.