Abstract: A computer system includes a bus system having a local bus unit, a memory bus unit, an input/output bus unit, and an expansion bus unit. A pluggable central processing unit circuit board includes a microprocessor, a pluggable memory circuit board coupled to the central processing unit circuit board through the memory bus unit, and a pluggable bridge circuit board coupled to the central processing unit circuit board. A plurality of connectors includes a first connector unit for receiving the pluggable central processing unit circuit board; a second connector unit for receiving the pluggable memory circuit board; and a third connector unit for receiving the pluggable bridge circuit board. The third connector unit is coupled to the first connector unit of the central processing unit circuit board through the bus system. A plurality of peripheral devices are coupled to the bridge circuit board through the input/output bus unit.

Abstract: An improved memory controller within a data processing system having a look-aside cache architecture is disclosed. The data processing system includes a processor having an upper level cache associated therewith, a memory controller having an associated controller memory, a processor bus coupled between the processor and the memory controller, and a main memory. The data processing system further includes a lower level cache coupled to the processor bus in parallel with the processor and memory controller. According to a first aspect of the present invention, the memory controller includes logic, which in response to receipt of a write request that will not be serviced by the lower level cache and for which the associated data is not a replaced modified cache line, stores the associated data within the controller memory associated with the memory controller, thereby optimizing data storage within the data processing system.