Reducing cache hierarchy energy consumption by predicting forwarding and disabling associative sets

The first level data cache in modern processors has become a major consumer of energy due to its increasing size and high frequency access rate. In order to reduce this high energy consumption, we propose in this paper a straightforward filtering technique based on a highly accurate forwarding predi...

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Detalles Bibliográficos
Autores: Carazo, Pablo, Apollini, Ruben, Castro Rodríguez, Fernando, Chaver Martínez, Daniel Ángel, Piñuel Moreno, Luis, Tirado Fernández, José Francisco
Tipo de recurso: artículo
Fecha de publicación:2012
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/44467
Acceso en línea:https://hdl.handle.net/20.500.14352/44467
Access Level:acceso abierto
Palabra clave:004
Energy consumption
Filtering
Forwarding predictor
Cache hierarchy
Informática (Informática)
1203.17 Informática
Descripción
Sumario:The first level data cache in modern processors has become a major consumer of energy due to its increasing size and high frequency access rate. In order to reduce this high energy consumption, we propose in this paper a straightforward filtering technique based on a highly accurate forwarding predictor. Specifically, a simple structure predicts whether a load instruction will obtain its corresponding data via forwarding from the load-store structure - thus avoiding the data cache access - or if it will be provided by the data cache. This mechanism manages to reduce the data cache energy consumption by an average of 21.5% with a negligible performance penalty of less than 0.1%. Furthermore, in this paper we focus on the cache static energy consumption too by disabling a portion of sets of the L2 associative cache. Overall, when merging both proposals, the combined L1 and L2 total energy consumption is reduced by an average of 29.2% with a performance penalty of just 0.25%.