Light NUCA: A proposal for bridging the inter-cache latency gap

Abstract—To deal with the “memory wall” problem, microprocessors include large secondary on-chip caches. But as these caches enlarge, they originate a new latency gap between them and fast L1 caches (inter-cache latency gap). Recently, NonUniform Cache Architectures (NUCAs) have been proposed to sustain the size growth trend of secondary caches that is threatened by wire-delay problems. NUCAs are size-oriented, and they were not conceived to close the inter-cache latency gap. To tackle this problem, we propose Light NUCAs (L-NUCAs) leveraging on-chip wire density to interconnect small tiles through specialized networks, which convey packets with distributed and dynamic routing. Our design reduces the tile delay (cache access plus one-hop routing) to a single processor cycle and places cache lines at a finer granularity than conventional caches, reducing cache latency. Our evaluations show that in general, an L-NUCA improves simultaneously performance, energy, and area when integ...

• Type: Conference
• Year: 2009
• Where: DATE
• Authors: Darío Suárez Gracia, Teresa Monreal, Fernando Vallejo, Ramón Beivide, Víctor Viñals
• Keywords: DATE 2009, Hardware, Inter-cache Latency Gap, Latency Gap, Secondary On-chip Caches