So my current research is focused on the spinnaker project
Spinnaker is a crude
Contraction of spiking Neural Network Architecture [well] the goal is [to] build a machine
incorporating a million arm processor cores
Which we can use for real-time brain modeling applications now with a million cores we only get to about
1% of the scale of the human Brain [or]
[as] I [prefer] to think of it 10
Whole mouse brains which gives you some idea of the scale of the problem that that we're taking on here
The physical machine occupies or will occupy 10 19-inch racks, so these are
Standard [datacenter] cases about 6 [to] 7 feet tall [a]
Bit over 90 inches wide and about a [metre] deep the machine will be built here in [Manchester] and be based in Manchester
We this stage we have one of those racks populated so a hundred thousand cores
Which is about one mouse brains worth in terms of Network complexity [of] course?
modeling a real mouse brain requires lots of biological detail that's that we won't be going into and
knowledge of the Network that doesn't currently exist, but
Just gives you a feel of the scale of network that we can model on the machine
the physical design of Spinnaker is really reasonably conventional and
We have the chips each of which has 18 cores on
We mount 48 of those chips on the circuit board which is about the size of an A4 sheet of paper
so that gives you the [order] of a thousand processors on a circuit board and then we stack the
circuit boards in card frames, so they're plugged into
into standard racks
Quite close together and which we can do because we've been very careful to keep the power consumption under control
So there are no real [hotspots] on the board and therefore, it's quite
Easy to [air-cool] even when they're spaced quite closely together so [we] can get 24 boards across the width of a 19 inch card frame
And we can stack those
[5] frames high in A 19-inch rack
Including allowing space for cooling and so on and and that gives you
120 boards each with a and [864] processors, which is a hundred thousand?
over 100,000 processors in the 19-inch rack
so with the PCBs
Look pretty conventional. They're just lots of little black plastic packages and sold it together in a slightly unusual irregular array
The thing you'd notice about the board is it is highly regular I can show you one if you want it would love to see
One yeah is the one yeah yeah can we show [sigh] yeah, so this is
One of the Spinnaker boards this one's packaged
in its own acrylic box
you can see the spinnaker chips the
the name gives us an
Obvious logo of a spinnaker sail which is quite attractive and easy to put on the chip so you can see there are 48
Chips on this board it may look [like] they're arranged in a square, but actually
Topologically they're in a hexagon, so the board is a hexagonal sub surface of the toroid
the
the boards have high speed connectors on the Edges and
That allows us to connect multiple boards together to build the larger systems
So when we put a hundred thousand cause in a rack all the boards in that rocker arranged on a single continuous toroid
Which keeps the communication efficient.
So, so this is a [nineteen] inch card frame with [twenty-four] spinnaker boards in twenty thousand arm processors
And you can see the boards are all linked together through high speed links which puts the chips into a continuous single
toroidal surface
And then the boards are connected through a network switch to an ethernet system. Which is
Used for loading software onto the machine on the top of the box
there's a robot with a single spinnaker card on its back the robot is built by
your conrad at the technical university of Munich and it has a couple of
vision Sensors from Toby dell Brook at the University of Zurich on the front and that can be used to build simple Neural robot
controllers that run on the spinnaker board
That's a [single-car]. That's basically controlling the robot twice eight hundred and sixty four processors. Which is more than
a robot will usually get
Are we going now? I'll show you the big machine. That's sir. Yes, so we're walking through the it building here and
So this is a [hundred-thousand] processor spinnaker machine
it has five [of] the card frames that we
Saw in the previous shot [and] now you can see the wiring that wires them together. That's got a lot more complicated and stringy
The primary problems is it all the wiring yes? It's quite complicated to wire it took a phd student
[four] hours to wire the machine up in the front the machine is basically connected [to] the ethernet
So you can control it remotely
You need some kind of host machine to compile the network on and you download it over the net onto
the Spinnaker machine itself and then
The thing then runs and the network evolves in real time even the small card frames a bit noisy
[we] were very careful about the power consumption that
It was still packing it together sufficiently densely that it needs a bit of a draft to keep it cool
Apart from the communications network the spinnaker architecture looks reasonably conventional is it's a massively parallel
Computer each node is an arm processor with a certain amount of code memory and a certain amount of Data memory
And so programming the processor caused themselves is reasonably conventional because we're aiming for real time
We use what's called an event-driven programming model. So instead of having a single program [that] runs and loops around
The programmer writes a number of event handlers which a little bit of little bits of code that get invoked
When particular events happen such as an incoming packet arrives from another neuron
That in that calls a little bit of code which says well
What do I do when this input spikes and what I do is I?
Look up the synapse is that are connected to that import?
And I pass the relevant level of signal through to the neurons that [are] modeled here
and
that may or may not cause some [of] those neurons to spike and if they do then I drop more packets into the fabric and
So on the design objective of spinnaker was to model about a thousand neurons
In real time on each arm core so with a million core machine we get to a billion neurons in total now
at the moment we're still tweaking the efficiency of [the] software and the current software implementation maps about
[256] Neurons to each core so so we aren't at the efficiency
We're ultimately aiming for but we're close the basis of human memory [is] not really well, understood
I mean computer memory is relatively very simple
We arrange a silicon structure and we have a cell where we can store a naught or a 1 and we know exactly where that
[information] is and if the cell breaks we lose that information
Human memory doesn't seem to be like that human memory seems to be much more distributed
we all
through adult life losing about a neuron a second
And so if he any in your wrong was critical to a memory then each neuron we lost will be some memory going
And that doesn't seem to be the case it seems to be that
[biology] has found ways [to] store information in distributed ways, so if you lose small components
you don't lose the memory the aim of building the spinnaker machine was to contribute to the
Scientific ground challenge [of] understanding how the brain works we have we each have this thing inside our heads that
Is clearly vital to the way we perform our daily tasks
But we don't know how it works fundamentally as an information processor. We don't have
Deep Knowledge, we know lots about the fine detail about about the neurons and the cellular biology
And we know quite a lot about how activity moves around inside the head, but the interesting stuff about
For me as a computer scientist is how information is processed
And that's the levels that we can't access either from the bottom up or from the top down
So [really] the only instruments we have for
increasing our understanding are
computer models now of course
The computer models have to be informed by what we do know about
Neuroscience, so
so this work is very much a collaboration between
disciplines and Neuroscience computer science
psychology, all come into play with quite a lot of mathematics -
It's a little bit similar to the yellow one
so we put it'll be closer to the yellow one and then comes another data item and no this is obviously quite similar to the
Yellow one to be put it closer to here
don't want to just - something off, but I
Read it off make [sure] that my sentences are well constructed and spelled correctly and so on so it took a long time and it
Turned out that. I was spending
You know I would start out with an idea of what I could do that day, and then four hours later