Memory OmniScriptum Memory Controller: Main memory, Die (integrated circuit), Microprocessor, Intel, Northbridge (computing)

Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The memory controller is a digital circuit which manages the flow of data going to and from the main memory. It can be a separate chip or integrated into another chip, such as on the die of a microprocessor. Computers using Intel microprocessors have traditionally had a memory controller implemented on their motherboard's northbridge, but some modern microprocessors, such as DEC/Compaq's Alpha 21364, AMD's Athlon 64 and Opteron processors, IBM's POWER5, Sun Microsystems UltraSPARC T1 and more recently, Intel Core i7 have a memory controller on the microprocessor die to reduce the memory latency. While this has the potential to increase the system's performance, it locks the microprocessor to a specific type of memory, forcing a redesign in order to support newer memory technologies. When DDR2 SDRAM was introduced, AMD released new Athlon 64 CPUs. These new models, with a DDR2 controller, use a different physical socket, so that they will only fit in motherboards designed for the new type of RAM. When the memory controller is not on-die, the same CPU may be installed on a new motherboard, with an updated northbridge.