On randomly interleaved memories

The authors analyze and identify a basic deficiency of a class of random interleaving schemes (LINEAR), which use linear transformation techniques to achieve randomization. Since all bank addresses generated by these methods are random, constrained only by the bijective property, more conflicts tend to occur than in the more common MODULO method. Also LINEAR lacks the capability of MODULO to move several conflicting vector streams to a conflict-free steady state. To correct these deficiencies, a new class of random interleaving schemes called RANDOM-H that hash only the higher-order address bits is proposed. Unlike LINEAR, the RANDOM-H schemes randomize selectively, while retaining some of the advantages of MODULO. It is shown that RANDOM-H has a higher probability of accessing a vector without conflict than LINEAR. An an example of RANDOM-H, a method called MASH is presented that combines module interleaving with a multiplicative hashing function for randomization