[Colloquium] Reminder: Jokar/MS Presentation/Feb 1, 2019

[Margaret Jaffey via Colloquium]

This is a reminder about Reza Jokar's MS Presentation today.

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Date:  Friday, February 1, 2019

Time:  3:00 PM

Place:  John Crerar Library 298

M.S. Candidate:  Mohammad Reza Jokar

M.S. Paper Title: A High-Performance and Energy-Efficient Optical
Network Using Transistor Laser

Abstract:
We present an all-optical network, Baldur, which is capable of
supporting energy-efficient and high-speed communications in future
exascale computing systems. The essence of Baldur is its ability to
perform packet switching on-the-fly in the optical domain using an
emerging technology called transistor laser (TL), which presents
interesting opportunities and challenges in the system level. Optical
packet switching readily eliminates many inefficiencies associated
with the crossing between optical and electrical domains. On the other
hand, TL gates offer limited logic functions and consume high power
(two orders of magnitude higher than CMOS gates), which requires novel
architecture and logic design approaches that are drastically
different from those adopted in current networks.

We overcome the major challenges in Baldur by investigating techniques
that are optimized for TL-based all-optical switches. At the
architecture level, we find that a bufferless multi-stage network with
a simple routing algorithm that drops packets to handle congestion is
strongly preferred, and we explore incorporating path multiplicity and
randomness to minimize packet drops. At the logic design level, a
non-conventional data encoding scheme is used to overcome major
inefficiencies in TL gates.

We thoroughly validate and evaluate Baldur using a circuit simulator
and a detailed network simulator. Our results show that Baldur
consumes up to 5.88X less power, and at the same time dramatically
improves packet latency by up to 709.39X (52.59X on geometric mean)
compared to existing state-of-the-art networks under
throughput-oriented synthetic traffic patterns, for the scale of 1024
server nodes. It also improves the execution time by up to 8.36X
(2.11X on geometric mean) under real workloads and latency-oriented
synthetic traffic patterns. This means that, while large-scale
electrical multi-stage networks are generally considered inefficient
in practice, our architecture and logic design techniques allow
Baldur, despite being constructed using high-power and restrictive TL
gates, to significantly outperform state-of-the-art designs. Baldur is
also highly scalable, and its benefit increases as the network scales.
For example, for 1 million server nodes, Baldur achieves up to 9.05X
improvement in power.

Mohammad Reza's advisors are Prof. Frederic Chong and Prof. Yanjing Li

Login to the Computer Science Department website for details:
 https://newtraell.cs.uchicago.edu/phd/ms_announcements#jokar

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Margaret P. Jaffey            margaret at cs.uchicago.edu
Department of Computer Science
Student Support Rep (Ry 156)               (773) 702-6011
The University of Chicago      http://www.cs.uchicago.edu
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