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Connection Machine -1-2-5
* from http://www.nas.nasa.gov/Pubs/TechReports/RNRreports/hsimon/RNR-92-016/subsection3_2_12.html#SECTION00021200000000000000
|Manufacturer ||Thinking Machines Corporation
|Date of first manufacture||1985
|Number produced ||-
|Estimated price or cost||-
|location in museum ||-
|donor ||David Yakimischak, Dow Jones & Company, Inc.
Laboratory for Computer Science, M. I. T.
Laboratory for Computer Science, M. I. T.
Contents of this page:
12 dimension hypercube
- from http://mission.base.com/tamiko/theory/cm_txts/di-frames.html
For Danny Hillis, a student working on problems in human cognition at the
Massachusetts Institute of Technology's Artificial Intelligence Laboratory in the
late '70s, existing sequential supercomputers were simply inadequate for the
problems that interested him. Even the fastest supercomputers were unable to
recognize human faces, use language at the level of a 5-year-old child, or perform
other tasks that humans, equipped with brains much slower than any
supercomputer, could solve with ease. He became convinced that it was necessary
to design a parallel computer with a structure closer to that of a human brain.
In order to build the first of these new machines, Hillis helped found Thinking
Machines Corporation in 1983, which introduced the CM-1 in 1986 and the higher
performance version, the CM-2, in 1987. (Since the CM-2 quickly replaced the
CM-1, being a faster version of the same computer architecture, as well as using the
same external package, I will speak only of the CM-2 from now on.) These
machines had 65,536 simple 1-bit processors that could simultaneously perform the
same calculation, each on its own separate data set. For problems involving the
separate but interrelated actions of many similar objects or units, such as movement
of atoms, fluid flow, information retrieval, or computer graphics, this "data-parallel"
structure brought tremendous increases in speed while also being easy to program.
Many problems that seemed impossibly complex when analyzed with sequential
logic fit naturally into a parallel data structure. (3)
This type of massively parallel architecture had been tried before, but what enabled
the CM-2 to succeed where other designs had failed was an extremely flexible and
fast communications network between the processors. Using the model of the
human brain, Hillis's design placed importance not so much on the processors
themselves, but rather on the nature and mutability of the connections between
them, hence the name "Connection Machine."
many identical interconnected processors under
the supervision of a single control unit, see figure 7.1.2. The control unit
transmits the same instruction, simultaneously, to all processors.
All the processing elements simultaneously execute the same instruction and are
said to be 'lock-stepped' together. Each processor works on data from its own
memory and hence on distinct data streams. (Some systems also provide a shared
global memory for communications.) Every processor must be allowed to complete
its instruction before the next instruction is taken for execution. Thus, the
execution of instructions is said to be synchronous.
This category corresponds to the array processors discussed in section 2.3.3
and examples include; ILLIAC-IV, PEPE, BSP, STARAN, MPP, DAP and the
Connection Machine (CM-1).
- The Connection Machine CM-1 has 65,536 simple 1-bit processors connected into a
hypercube and each having 4Kbits of memory. Every processor is connected to a
central unit called the 'microcontroller' which issues identical 'nanoinstructions'
to all of them. This unit can be regarded as a control unit.
Processors Grain Topology Control Multiplicity
V S Hypercube V
- It should be noted that the CM-1 is not very efficient when doing floating-point
calculations. In the development it turned out that floating-point performance
was very important for the commercial success of such a massively parallel computer.
- Therefore in the CM-2, the memory size was increased (to 64K or 256K per processor)
and special floating-point accelerators were added. These chips were added one
for each 32 1-bit processors, corresponding to the 32-bit width of one
- In further development, the principle of using custom build hardware for the
processors was abandoned, because commercial microprocessors were gaining in
speed much faster than could be achieved with custom hardware. The next
generation [CM-5] of connection machines used standard microprocessors,
thus abandoning the SIMD principle.
- By now (1996) Thinking Machines
Corporation has abandoned the hardware development, and now focuses on
software development for massively parallel computers constructed by other companies.
Danny Hillis writes first description of the Connection Machine
architecture (appears as memo from Artificial Intelligence Lab at
MIT). (BMB: TMC, Connection Machine)
DARPA starts Strategic Computing Initiative, which helps fund such
machines as Thinking Machines Connection Machine, BBN Butterfly, WARP
from Carnegie Mellon University and iWarp from Intel Corp. (MW:
TMC demonstrates first CM-1 Connection Machine to DARPA. (BMB: TMC,
Thinking Machines Corp. ships first Connection Machine CM-1 (up to
65536 single-bit processors connected in hypercube). (GVW: TMC, CM-1)
TMC introduces CM-2 Connection Machine (64k single-bit processors
connected in hypercube, plus 2048 Weitek floating point units). (GVW:
Gordon Bell Prize for absolute performance awarded to a team from
Mobil and Thinking Machines Corporation, who achieved 6 GFLOPS on a
CM-2 Connection Machine; prize in price/performance category awarded
to Emeagwali, who achieved 400 MFLOPS per million dollars on the same
platform. (GVW: Gordon Bell Prize)
Gordon Bell Prize in price/performance category awarded to Geist,
Stocks, Ginatempo, and Shelton, who achieved 800 MFLOPS per million
dollars in a high-temperature superconductivity program on a 128-node
Intel iPSC/860; prize in compiler parallelization category awarded to
Sabot, Tennies, and Vasilevsky, who achieved 1.5 GFLOPS on a CM-2
Connection Machine with Fortran 90 code derived from Fortran 77.
(GVW: Gordon Bell Prize)
Thinking Machines Corporation produces CM-200 Connection Machine, an
upgraded CM-2. MIMD CM-5 announced. (BMB: TMC, CM-200)
Interesting Web Sites
From: Steve Pothier
Date: Wed, Nov 23, 2016
My wife asked you something about CM and found you were looking for stories. Here's mine:
In 1987 I was do some work in Artificial Intelligence. I became a big fan of Marvin Minsky. That led me to someone I had not heard of before: Danny Hillis. I bought Danny's PhD dissertation (about the Connection Machine) and read it. About that time I interviewed at a company that didn't seem all that appealing at the time: Science Applications International Corporation. During the interview, a manager mentioned that they probably had access to every kind of super-computer except a Cray in the office. I more or less mumbled: "probably not a Connection Machine". That manager heard (good ears!) and said: "Did you say Connection Machine? We have one downstairs. Do you want to see it.". I want from "I don't want this job" to "I'll sell my first-born to get it" in a flash! When I got an offer to work on the CM at SAIC I told my wife I would do it for free. She thought that was not the best negotiating position and suggested I keep that idea to myself. Smart lady.
When was hired, I was a "Connection Machine" expert despite the fact that the only thing I new about it was from reading Danny's dissertation. I did make that clear to SAIC but as is often the case "expert" just means "knows more than anyone else in the room". Before SAIC, I was programming in Lisp and the CM was programmed in "*Lisp" so it was a great fit. I spent several years doing my dream job. It was very difficult to pull myself away and go home at the end of the day. Our use of the CM was through DARPA. Eventually contracts moved on, "our" CM was taken away. I did some other CM work on a remote machine for awhile after before switching to more traditional architectures.
If you hear of any actual CM-2's that are up an running anywhere, I would love to know about them! I still long to do that kind of data-parallel programming and would consider just about anything to be able to do it again.
If you have comments or suggestions, Send e-mail
to Ed Thelen
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Updated February 3, 2003, Nov 2016