TY - GEN
T1 - Dynamic bandwidth scaling for embedded DSPs with 3D-stacked DRAM and wide I/Os
AU - Chang, Daniel W.
AU - Son, Young Hoon
AU - Ahn, Jung Ho
AU - Kim, Hoyoung
AU - Ahn, Minwook
AU - Schulte, Michael J.
AU - Kim, Nam Sung
PY - 2013
Y1 - 2013
N2 - 3D main memory is an emerging technology that stacks DRAM dies underneath the processor die using through-silicon vias (TSVs). Prior studies assumed that such technology would decrease main memory access latency by 45% to 60%, while also allowing designers to increase main memory bandwidth. Although the latter is true, it was recently shown that the latency savings of 3D main memory is only 6.3%. In this paper, we first analyze memory latency reduction opportunities in a 3D main memory system with Wide I/O by taking better advantage of 3D integration technology and quantify their benefit. Specifically, redesigning the DRAM to memory controller synchronizers and placing the address, command, and data pads closer to the DRAM banks can decrease 3D main memory latency by 24.7%. We show that current 3D DRAM with Wide I/O can increase the geometric mean performance of an embedded processor that is similar to a Texas instrument C67x DSP by 9.7% (and up to 23.3%). Second, we observe that 3D DRAM with Wide IO can increase average system energy consumption of energy-constrained embedded DSPs by 2.6% (and up to 8.9%). To improve I/O energy efficiency, we propose to dynamically scale memory bandwidth (i.e. the I/O width) at runtime based on an application's program phases. Our dynamic bandwidth scaling algorithms increase average performance by 6.6% while increasing average energy consumption by only 0.5%.
AB - 3D main memory is an emerging technology that stacks DRAM dies underneath the processor die using through-silicon vias (TSVs). Prior studies assumed that such technology would decrease main memory access latency by 45% to 60%, while also allowing designers to increase main memory bandwidth. Although the latter is true, it was recently shown that the latency savings of 3D main memory is only 6.3%. In this paper, we first analyze memory latency reduction opportunities in a 3D main memory system with Wide I/O by taking better advantage of 3D integration technology and quantify their benefit. Specifically, redesigning the DRAM to memory controller synchronizers and placing the address, command, and data pads closer to the DRAM banks can decrease 3D main memory latency by 24.7%. We show that current 3D DRAM with Wide I/O can increase the geometric mean performance of an embedded processor that is similar to a Texas instrument C67x DSP by 9.7% (and up to 23.3%). Second, we observe that 3D DRAM with Wide IO can increase average system energy consumption of energy-constrained embedded DSPs by 2.6% (and up to 8.9%). To improve I/O energy efficiency, we propose to dynamically scale memory bandwidth (i.e. the I/O width) at runtime based on an application's program phases. Our dynamic bandwidth scaling algorithms increase average performance by 6.6% while increasing average energy consumption by only 0.5%.
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U2 - 10.1109/ICCAD.2013.6691198
DO - 10.1109/ICCAD.2013.6691198
M3 - Conference contribution
AN - SCOPUS:84893366819
SN - 9781479910717
T3 - IEEE/ACM International Conference on Computer-Aided Design, Digest of Technical Papers, ICCAD
SP - 747
EP - 754
BT - 2013 IEEE/ACM International Conference on Computer-Aided Design, ICCAD 2013 - Digest of Technical Papers
T2 - 2013 32nd IEEE/ACM International Conference on Computer-Aided Design, ICCAD 2013
Y2 - 18 November 2013 through 21 November 2013
ER -