The present invention provides methods and apparatus for transferring and storing data among processors and memory in a multiprocessor system. The data is compressed locally before it is sent to a shared memory. The memory stores the data in its compressed state, but the data is aligned in the memory in the same manner as uncompressed data would be. A tag table keeps track of the compression type and compressed data size for a set of data at a given address block. A data compressor and a data expander may be implemented in a direct memory access controller accessible to multiple coprocessors, or the compressor and the expander may be implemented within the coprocessors.