A computer system includes a memory hub for coupling a processor to a
plurality of synchronous dynamic random access memory ("SDRAM") devices.
The memory hub includes a processor interface coupled to the processor
and a plurality of memory interfaces coupled to respective SDRAM devices.
The processor interface is coupled to the memory interfaces by a switch.
Each of the memory interfaces includes a memory controller, a cache
memory, and a prediction unit. The cache memory stores data recently read
from or written to the respective SDRAM device so that it can be
subsequently read by processor with relatively little latency. The
prediction unit prefetches data from an address from which a read access
is likely based on a previously accessed address.