Abstract: According to the present invention, methods and apparatus are provided to allow dynamic multiple cluster system configuration changes. In one example, processors in the multiple cluster system share a virtual address space. Mechanisms for dynamically introducing and removing processors, I/O resources, and clusters are provided. The mechanisms can be implemented during reset or while a system is operating. Links can be dynamically enabled or disabled.

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 without the use of a dedicated wire.

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.

Abstract: Improved techniques are provided for detecting and correcting errors and skew 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 serialized and encapsulated as inter-cluster packets for transmission on inter-cluster links, preferably with link-layer encapsulation. Each inter-cluster packet may include a sequence identifier and error information computed for that packet. Clock data may be embedded in symbols sent on each bit lane of the inter-cluster links. Copies of transmitted inter-cluster packets may be stored until an acknowledgement is received.

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 multi-processor computer system is described in which address mapping, routing, and transaction identification mechanisms are provided which enable the interconnection of a plurality of multi-processor clusters, wherein the number of processors interconnected exceeds limited address, node identification, and transaction tag spaces associated with each of the individual clusters.

Abstract: A multi-processor computer system is described in which address mapping, routing, and transaction identification mechanisms are provided which enable the interconnection of a plurality of multi-processor clusters, wherein the number of processors interconnected exceeds limited address, node identification, and transaction tag spaces associated with each of the individual clusters.

Abstract: Improved techniques are provided for detecting and correcting errors and skew 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 serialized and encapsulated as inter-cluster packets for transmission on inter-cluster links, preferably with link-layer encapsulation. Each inter-cluster packet may include a sequence identifier and error information computed for that packet. Clock data may be embedded in symbols sent on each bit lane of the inter-cluster links. Copies of transmitted inter-cluster packets may be stored until an acknowledgement is received.

Abstract: A multi-processor computer system is described in which address mapping, routing, and transaction identification mechanisms are provided which enable the interconnection of a plurality of multi-processor clusters, wherein the number of processors interconnected exceeds limited address, node identification, and transaction tag spaces associated with each of the individual clusters.

Abstract: Improved techniques are provided for detecting and correcting errors and skew 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 serialized and encapsulated as inter-cluster packets for transmission on inter-cluster links, preferably with link-layer encapsulation. Each inter-cluster packet may include a sequence identifier and error information computed for that packet. Clock data may be embedded in symbols sent on each bit lane of the inter-cluster links. Copies of transmitted inter-cluster packets may be stored until an acknowledgement is received.

Abstract: Improved techniques are provided for detecting and correcting errors and skew 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 serialized and encapsulated as inter-cluster packets for transmission on inter-cluster links, preferably with link-layer encapsulation. Each inter-cluster packet may include a sequence identifier and error information computed for that packet. Clock data may be embedded in symbols sent on each bit lane of the inter-cluster links. Copies of transmitted inter-cluster packets may be stored until an acknowledgement is received.

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: 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: An interconnection controller for use in a computer system having a plurality of processor clusters is described. Each cluster includes a plurality of local nodes and an instance of the interconnection controller. The interconnection controller is operable to transmit locally generated interrupts to others of the clusters, and remotely generated interrupts to the local nodes. The interconnection controller is further operable to aggregate locally generated interrupt responses for transmission to a first remote cluster from which a first interrupt corresponding to the locally generated responses was generated. The interconnection controller is also operable to aggregate remotely generated responses for transmission to a first local node from which a second interrupt corresponding to the remotely generated responses was generated. A computer system employing such an interconnection controller is also described.

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: Improved techniques are provided for detecting and correcting errors and skew 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 serialized and encapsulated as inter-cluster packets for transmission on inter-cluster links, preferably with link-layer encapsulation. Each inter-cluster packet may include a sequence identifier and error information computed for that packet. Clock data may be embedded in symbols sent on each bit lane of the inter-cluster links. Copies of transmitted inter-cluster packets may be stored until an acknowledgement is received.

Abstract: Improved techniques are provided for detecting and correcting errors and skew 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 serialized and encapsulated as inter-cluster packets for transmission on inter-cluster links, preferably with link-layer encapsulation. Each inter-cluster packet may include a sequence identifier and error information computed for that packet. Clock data may be embedded in symbols sent on each bit lane of the inter-cluster links. Copies of transmitted inter-cluster packets may be stored until an acknowledgement is received.

Abstract: Improved techniques are provided for detecting and correcting errors and skew 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 serialized and encapsulated as inter-cluster packets for transmission on inter-cluster links, preferably with link-layer encapsulation. Each inter-cluster packet may include a sequence identifier and error information computed for that packet. Clock data may be embedded in symbols sent on each bit lane of the inter-cluster links. Copies of transmitted inter-cluster packets may be stored until an acknowledgement is received.

Abstract: Improved techniques are provided for detecting and correcting errors and skew 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 serialized and encapsulated as inter-cluster packets for transmission on inter-cluster links, preferably with link-layer encapsulation. Each inter-cluster packet may include a sequence identifier and error information computed for that packet. Clock data may be embedded in symbols sent on each bit lane of the inter-cluster links. Copies of transmitted inter-cluster packets may be stored until an acknowledgement is received.

Abstract: According to the present invention, methods and apparatus are provided to allow dynamic multiple cluster system configuration changes. In one example, processors in the multiple cluster system share a virtual address space. Mechanisms for dynamically introducing and removing processors, I/O resources, and clusters are provided. The mechanisms can be implemented during reset or while a system is operating. Links can be dynamically enabled or disabled.