Abstract: Cache coherence directory eviction mechanisms are described for use in computer systems having a plurality of multiprocessor clusters. Interaction among the clusters is facilitated by a cache coherence controller in each cluster. A cache coherence directory is associated with each cache coherence controller identifying memory lines associated with the local cluster that are cached in remote clusters. Techniques are provided for managing eviction of entries in the cache coherence directory by locking memory lines in a home cluster without causing a memory controller to generate probes to processors in the home cluster.

Abstract: An electronic assembly is described which includes a printed circuit board, and a processor and a memory mounted on the printed circuit board. A routing channel is provided in the printed circuit board comprising a plurality of conductors interconnecting the processor and the memory. A regulator assembly includes a regulator for providing power to the processor, a first connector mounted on the printed circuit board adjacent a first edge of the routing channel, and a second connector mounted on the printed circuit board adjacent a second edge of the routing channel opposite the first edge. The first and second connectors are coupled to the regulator and facilitate distribution of the power to the processor. The regulator and the first and second connectors form a bridge across the routing channel.

Abstract: According to the present invention, methods and apparatus are provided for increasing the efficiency of data access in a multiple processor, multiple cluster system. Mechanisms for reducing the number of transactions in a multiple cluster system are provided. In one example, probe filter information is used to limit the number of probe requests transmitted to request and remote clusters.

Abstract: According to the present invention, methods and apparatus are provided for static and dynamic power management of computer systems. A power authority manages power usage levels in computer systems by monitoring power consumption levels and providing power consumption information to the various systems. In one example, the power authority updates power tables to vary aggregate power consumption levels.

Abstract: A disk drive backplane is described which includes a connector for interfacing with a corresponding connector on each of a plurality of carrier types. A plurality of status indicator arrays is provided, each of which corresponds to at least one of the carrier types and is operable to transmit status information. Each of the arrays is positioned to interface with a corresponding status interface on the corresponding carrier type(s). Circuitry is provided which enables one of the status indicator arrays thereby configuring the backplane to interface with a particular one of the carrier types.

Abstract: Methods and devices are provided for controlling lock and unlock operations within a computer system. A home cluster includes a home lock manager. The home lock manager is a master lock manager for the home cluster and for a plurality of remote clusters, the plurality of remote clusters including remote cache coherency controllers and a plurality of remote processors. Lock and unlock commands from the home lock manager are transmitted by a home cache coherency controller to the remote cache coherency controllers and forwarded to the remote processors.

Abstract: Cache coherence directory eviction mechanisms are described for use in computer systems having a plurality of multiprocessor clusters. Interaction among the clusters is facilitated by a cache coherence controller in each cluster. A cache coherence directory is associated with each cache coherence controller identifying memory lines associated with the local cluster which are cached in remote clusters. An eviction manager is operable to designate one of the entries in the cache coherence directory to be evicted and maintain the designated entry in the cache coherence directory at least until a serialization point allows an eviction transaction corresponding to the designated entry to proceed.

Abstract: Cache coherence directory eviction mechanisms are described for use in computer systems having a plurality of multiprocessor clusters. Interaction among the clusters is facilitated by a cache coherence controller in each cluster. A cache coherence directory is associated with each cache coherence controller identifying memory lines associated with the local cluster which are cached in remote clusters. The cache coherence controller is operable to initiate eviction of an entry in its directory corresponding to an unmodified copy of a memory line by sending a request to write to the memory line to a corresponding memory controller.

Abstract: Cache coherence directory eviction mechanisms are described for use in computer systems having a plurality of multiprocessor clusters. Interaction among the clusters is facilitated by a cache coherence controller in each cluster. A cache coherence directory is associated with each cache coherence controller identifying memory lines associated with the local cluster which are cached in remote clusters. The cache coherence controller is operable to initiate eviction of an entry in its directory corresponding to a modified copy of a memory line by sending a request to merge an empty data field with the modified copy of the memory line to a corresponding memory controller.

Abstract: According to the present invention, methods and apparatus are provided for increasing the efficiency of data access in a multiple processor, multiple cluster system. Techniques are provided for speculatively probing a remote cluster from either a request cluster or a home cluster. A speculative probe associated with a particular memory line is transmitted to the remote cluster before the cache access request associated with the memory line is serialized at a home cluster. When a non-speculative probe is received at a remote cluster, the information associated with the response to the speculative probe is used to provide a response to the non-speculative probe.

Abstract: According to the present invention, methods and apparatus are provided for increasing the efficiency of data access in a multiple processor, multiple cluster system. Mechanisms for reducing the number of transactions in a multiple cluster system are provided. In one example, owning node information is used to limit the number of probes transmitted in a particular cluster.

Abstract: A disk drive backplane is described which includes a connector for interfacing with a corresponding connector on each of a plurality of carrier types. A plurality of status indicator arrays is provided, each of which corresponds to at least one of the carrier types and is operable to transmit status information. Each of the arrays is positioned to interface with a corresponding status interface on the corresponding carrier type(s). Circuitry is provided which enables one of the status indicator arrays thereby configuring the backplane to interface with a particular one of the carrier types.

Abstract: Improved techniques are provided for reducing latency in inter-cluster communications within computer systems having a plurality of multi-processor clusters. The local nodes of each cluster include a plurality of processors and an interconnection controller. Intra-cluster links are formed between the local nodes, including the interconnection controller, within a cluster. Inter-cluster links are formed between interconnection controllers of different clusters. Intra-cluster packets may be encapsulated as inter-cluster packets and stored in a transmission buffer pending transmission on an inter-cluster link. When the transmission buffer is empty, a control character is transmitted on an inter-cluster link. The control character is not stored in the transmission buffer or in a reception buffer, but instead is dropped. Clock data may be embedded in symbols sent on each bit lane of the inter-cluster links, including the symbol(s) of the control character.

Abstract: A basic input/output system (BIOS) for use in a computer system having a plurality of processors is described. The BIOS is embodied in a computer readable medium as computer program instructions which are operable to facilitate substantially simultaneous operation of the plurality of processors. According to one embodiment, the processors are simultaneously enabled to test of different portions of the system memory.

Abstract: An electronic assembly is described which includes a printed circuit board, and a processor and a memory mounted on the printed circuit board. A routing channel is provided in the printed circuit board comprising a plurality of conductors interconnecting the processor and the memory. A regulator assembly includes a regulator for providing power to the processor, a first connector mounted on the printed circuit board adjacent a first edge of the routing channel, and a second connector mounted on the printed circuit board adjacent a second edge of the routing channel opposite the first edge. The first and second connectors are coupled to the regulator and facilitate distribution of the power to the processor. The regulator and the first and second connectors form a bridge across the routing channel.

Abstract: According to the present invention, methods and apparatus are provided for increasing the efficiency and effectiveness of communications between multiprocessor clusters. Mechanisms for improving the accuracy of information available to an interconnection controller are implemented in order to allow the interconnection controller to increase reliability and reduce latency in a multiple cluster system. Protocol extensions and link layer extensions are provided with packets to convey information between interconnection controllers of separate multiprocessor clusters.

Abstract: One embodiment of the disclosures made herein is a method for facilitating replication of a service processor configuration. In accordance with such an embodiment, an operation is performed for requesting configuration data required for facilitating replication of at least a portion of a baseline service processor configuration onto a first service processor. The operation of requesting is performed by the first service processor and a configuration dataset maintained on the first service processor represents a service processor configuration of the first service processor. After requesting the required configuration data, an operation is performed for accessing the required configuration data within a configuration dataset maintained on a second service processor. The configuration dataset maintained on the second service processor represents the baseline service processor configuration.

Abstract: According to the present invention, methods and apparatus are provided for increasing the efficiency of data access in a multiple processor, multiple cluster system. Mechanisms for allowing a variety of transactions to complete locally are implemented by providing remote data caches associated with the various clusters in the system. The remote data caches receive data and state information for memory lines held in remote clusters. State information is provided to the remote data cache using various mechanisms including a coherence directory and augmented source done messages.

Abstract: A computer system is described having a plurality of processing nodes interconnected by a first point-to-point architecture, and a system memory including a plurality of portions each of which is associated with one of the processing nodes. Each processing node includes a processor, and a memory controller for controlling access to the associated portion of the system memory, and may contain a host bridge for facilitating communication with a plurality of I/O devices. The first point-to-point architecture is operable to facilitate first transactions between the processors and the system memory. The computer system further includes at least one I/O controller and a second point-to-point architecture independent of the first point-to-point architecture and interconnecting the I/O controller and the host bridges. The at least one I/O controller is operable to facilitate second transactions between the I/O devices and the system memory via the second point-to-point architecture.

Abstract: Methods and apparatus are provided for improving the distribution of system management signals within a computer system complex. Mechanisms are provided for transmission both within a box and between computer system boxes. Local routing tables and general routing tables allow the distribution of system management signals precisely to resources associated with particular partitions. Signals are sequenced to put resources associated with one or more boxes in the appropriate states. The distribution of signals between boxes in the computer system complex can be accomplished with the use of a dedicated wire.