Open Access
Puttasiddaiah, Yogitha
Graduate Program:
Computer Science and Engineering
Master of Science
Document Type:
Master Thesis
Date of Defense:
November 21, 2008
Committee Members:
  • Dr Yuan Xie, Thesis Advisor
  • Yuan Xie, Thesis Advisor
  • 3D
  • NUCA
It’s a well known fact that memory performance is not keeping up with processor performance. Where Processor performance is increasing at roughly 60% every year, memory performance is less than 10% [3]. Shrinking feature sizes further worsen the effect of interconnect delay making it a critical obstacle in improving the memory access time. The widening gap between processor performance and memory has forced today’s researchers to look new avenues to counter the problem. The first and most successful step to alleviate this gap is three-dimensional designs. Memory can be stacked directly on top of a microprocessor through 3D integration resulting in significant reduction in wire delay between the processor and the memory. Studies have shown significant performance, power and area benefits of such an approach compared to the conventional two-dimensional designs. Another approach to attack memory access time is to adopt on-chip network-based communication, the concept of Non-Uniform Cache Architectures (NUCA). NUCA architecture divides memory space into multiple banks which have different access latencies depending on their location relative to the processor. NUCA employs a packet-switched network between banks thus the access times are a function of where the data blocks are found. The first contribution of this work is we implement two major extensions to the CACTI 6.0 cache modeling tool. First, we add the ability to model three-dimensional cache. Second, we add the ability to model MRAM and PRAM memory technologies. The second contribution is a detailed comparison of the four different mainstream memory technologies, SRAM, DRAM, MRAM and PRAM in terms of performance, power and area in an architecture that combines the benefits of 3D and NUCA. The work also highlights that the 3D NUCA L2 architecture generates much better results than the conventional two-dimensional (2D) designs.