WatsonBradley Conn and Matthew Behlke

Overview● Supercomputer created by IBM● Has the ability to answer questions asked in a natural human language● Initial goal was to compete on jeopardy● It competed against the two best jeopardy champions and won● Everything is self contained (It had no access to the internet while competing)● Current use is mostly in the medical field● Watson has many elements of machine learning and must therefore be

“trained” when being applied to new topics and tasks

General Hardware Specs● 90 IBM Power 750 Servers● 3.5GHz eight core with 4 threads per core● 2880 simultaneous threads● 80 TeraFLOPS● 16 Terabytes of RAM● Would be placed at around 100th most

powerful supercomputer in the world at the time

More Hardware specs● Uses Juniper Switches running at 10Gbps to connect the servers● split up into 10 racks● Costs approximately $34,000 per server or approximately $3 million overall● Answers questions in under 3 seconds● Could be scaled down linearly● Example: 9 servers would take approximately 30 seconds to answer a

question.

Content

● 400 Million pages of structured and unstructured content● Consumed 4 Terabytes of disk space● Includes all of wikipedia● Many previous jeopardy questions● The Internet Movie DataBase (IMDB)● Many research papers and news articles● Dictionaries and thesauri● Music databases

Software● DeepQA

○ Used for recognition of human speech rather than just keywords

● Apache UIMA framework○ Unstructured Information Management Architecture

○ Used to analyze large volumes of unstructured information to discover knowledge to the end user

● SUSE Linux Enterprise Server 11○ This was the Operating System used○ Also uses Apache Hadoop framework for distributed computing

■ Hadoop allows work to be divided and dispatched to different task engines and then combined back later

● Most of the software was written in Java and C++

DeepQA● Generates and scores many

hypotheses○ Natural language processing○ Machine learning○ Reasoning algorithms

● Gather weight and evidence to determine the answer with the best confidence

Structured vs Unstructured

POWER7 750● Uses Power Architecture ISA● Superscalar● Implements instruction level parallelism● Symmetric multiprocessor● Cache

○ Embedded DRAM (eDRAM) technology○ L1 cache 32KB○ L2 cache 256KB

■ 8 clock cycle penalty and 8 way set associative○ L2.5 cache up to 4 MB

■ Part of L3 cache■ Close arrays to the processor have access to these■ ⅕ the latency of true L3 cache (8 cycles)

○ L3 cache 32MB including L2.5

More POWER 750 Features● W-Y-Z buses connecting chips● Harvard● Out of Order instruction execution● 8 instructions per cycle● 12 instruction execution units

○ including load/store, integer, FP, vector● 45nm technology● 1.2 billion transistors● Dual DDR3 DRAM controllers

○ combined 100 GB/s bandwidth○ 16 kB RAS rescheduling buffer

Symmetric Multiprocessor System● Shared global memory space between processors● Only works between homogenous processors● OS only sees one memory space● Data transferred over shared bus using a crossbar switch● Allows node clusters to look like a single system without message passing

Turbo charge mode● 4 of the 8 cores are inactive● Clock frequency increases by over 18% up to 4.14GHz● More L3 cache per core● Nearly doubles bandwidth of the cache for the active cores

Power 7 power management● There are two ways to lower power consumption when parts of the chip are

idle for some time● Nap mode

○ Caches and TLBs stay active○ Can re-activate quickly

● Sleep mode○ Caches are purged○ The clock is turned off○ Minimum voltage to maintain memory is applied○ Wake up time is longer○ Power saving is very significant

Power Architecture● RISC ISA● Replaced POWER ISA● Designed by IBM and Freescale● Load/store architecture● 32 GPRs, 64 128-bit VSRs● 32 bit instructions● Divided into 5 parts called “Books”

Power Architecture Books● Book I - User instruction set architecture● Book II - Virtual Environment Architecture● Book III - Operating Environment Architecture

○ Book III-S○ Book III-E

● Book VLE - Variable Length Encoded Instruction architecture

Sources● http://www.edn.com/electronics-news/4314117/IBM-Power7-architecture-illustrates-some-issues-for-the-rest-of-us

● http://www.hpcresearch.nl/euroben/Overview/web12/power7.php

● http://www.slideshare.net/obsidiansoft/ludden-power7-verification

● http://www-03.ibm.com/systems/resources/systems_i_pwrsysperf_turbocore.pdf

● https://www.youtube.com/watch?v=uDBZnaoJVlk

● http://ieeexplore.ieee.org/xpl/tocresult.jsp?isnumber=6177717&cm_mc_uid=08782612124414494276953&cm_mc_sid_50200000=1449598501

● https://www.ibm.com/developerworks/community/blogs/InsideSystemStorage/entry/ibm_watson_how_to_build_your_own_watson_jr_in_your_basement7?lang=en

● http://www-03.ibm.com/press/us/en/pressrelease/29315.wss