Reducing interference among vector accesses in interleaved memories

Memory interference occurs when two or more concurrent data requests are addressed to the same main memory bank. In vector superconductors, this problem is serious due to the periodic interaction among vectors accesses, and can significantly reduce memory bandwidth and overall system performance. Two techniques can be used to reduce the effects of memory interference. First, vector data can be placed in the main memory such that, when accessed concurrently, the vectors do not interfere with one another. Second, buffers can be used at the memory banks to hold conflicting requests and to allow vector streams to continue to access other banks. Conditions for arbitrary numbers of vector streams to access an interleaved memory system without conflict are derived. It is shown that when three or more vector streams must be accessed concurrently, vector data placement to avoid conflicts becomes increasingly difficult, and that bank buffers can be effective under these conditions in increasing the effective memory bandwidth