Rainbow: a composable coherence protocol for multi-chip servers

The use of multi-chip modules (MCM) and/or multi-socket boards is the most suitable approach to increase the computation density of servers while keep chip yield attained. This article introduces a new coherence protocol suitable, in terms of complexity and scalability, for this class of systems. Th...

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Detalles Bibliográficos
Autores: Gregorio Menezo, Lucía, Puente Varona, Valentín|||0000-0002-6904-3282, Gregorio Monasterio, José Ángel|||0000-0003-2214-303X
Tipo de recurso: artículo
Fecha de publicación:2020
País:España
Institución:Universidad de Cantabria (UC)
Repositorio:UCrea Repositorio Abierto de la Universidad de Cantabria
Idioma:inglés
OAI Identifier:oai:repositorio.unican.es:10902/39644
Acceso en línea:https://hdl.handle.net/10902/39644
Access Level:acceso abierto
Palabra clave:Coherence protocol
Multi-CMP
Scalable
Descripción
Sumario:The use of multi-chip modules (MCM) and/or multi-socket boards is the most suitable approach to increase the computation density of servers while keep chip yield attained. This article introduces a new coherence protocol suitable, in terms of complexity and scalability, for this class of systems. The proposal uses two complementary ideas: (1) A mechanism that dissociates complexity from performance by means of colored-token counting, (2) A construct that optimizes performance and cost by means of two functionally symmetrical structures working in the last level cache of each chip and each memory controller. The coordinated work of both structures minimizes the coherence-related effects on the average memory latency perceived by the processor. Our proposal is able to improve on the performance of a HyperTransport-like coherence protocol by from 25% to 60%.