Data Remapping for an Energy Efficient Burst Chop in DRAM Memory Systems

In modern day systems, main memory contributes significantly to the overall power consumption. One of the features provided by JEDEC DDR3 standard onwards is Burst Chop (BC) through which the Burst Length of the data access commands (CAS) can be configured. This work aims to improve the energy efficiency of the DRAM memory by exploiting the existing BC features for half writes (writes in which either the first half or second half of the cache block is dirty). We propose to change the mapping of words of a cache block to the DRAM devices in order to reduce the number of devices involved in half writes. With our new mapping, we achieve average memory power savings of 3.27% with negligible impact on performance.