A system and method are provided for using a system-on-chip (SoC) memory manager to optimize the use of off-chip memory modules. A SoC memory controller receives a request for a first data block, subsequent to shutting the first memory down, and determines that the first data block is stored in the first memory. A SoC memory switching core uses a memory map to translate the first data block address in the first memory module to a first data block address in the second memory module. If the first data block is present in an on-SoC cache, the first data block is supplied on the SoC data bus from the cache. Then, the cache is loaded with a plurality of data blocks from a corresponding plurality of addresses in the second memory module, associated with the first data block address.