Improving Energy Efficiency with Special-Purpose Accelerators
The number of transistors per chip and their speed grows exponentially, but the
power dissipation per transistor is decreased slightly with each process
generation. This leads to increased power density and heat generation, meaning
that only a fraction of the chip can be active at any given time. To attack this
problem, heterogeneous systems-on-chip are developed. They consist of multiple
specialized cores, each optimized to perform a particular set of tasks.
Delegating parts of the application to run on specific,
energy-efficient cores, allows more computations to execute within the given
power budget, increasing the overall performance of the system.
This thesis proposes a methodology for developing a special-purpose accelerator
for a given application to create an energy-efficient heterogeneous
system-on-chip based on the Xilinx Zynq platform. This work introduces the
Xilinx tool suite used during development and defines the complete design
work flow for implementing the accelerator and running the application on
the accelerated system. This work evaluates the optimization techniques
which lead to the most energy-efficient implementation. The simulations show
that pipelining, separate ports for reading and writing data and a small,
fast, local memory improves the performance of the accelerator by a factor
of 44.4x and the energy-efficiency by 379x.
The accelerator is physically implemented on the Xilinx Zynq SoC and acts as a
co-processor for the ARM CPU available on the system. This work proposes a
methodology for evaluating the physical power consumption and performance of various
configurations of the system. For the given application, the system with the
accelerator running at 125 MHz is 1.5x faster and 2.15x more energy-efficient
compared to the application executing only on the CPU at 666 MHz. If the clock
frequencies are matched at 100 MHz, the accelerated system is 3.6x faster and 3x
Place, publisher, year, edition, pages
Institutt for datateknikk og informasjonsvitenskap , 2013. , 77 p.
IdentifiersURN: urn:nbn:no:ntnu:diva-23451Local ID: ntnudaim:8953OAI: oai:DiVA.org:ntnu-23451DiVA: diva2:664087
Jahre, Magnus, Førstelektor