Too many synapses?

[Alfonso Yamamoto]

Hi,

I was trying to increment the number of synapses on my network.

See the attached photo for the setup.

Previously I was just using an AllToAllConnector() from the input layer to the hidden layer. That worked fine. Then I wanted to use a FromListConnector(), that would allow me to have multiple synapses between input neuron (SpikeSourceArray) and my model neuron. For instance, right now I would like to try to have four synapses; they can be either excitatory or inhibitory. 

But when I try to run my script I get the following:

I already tried to lower the number of neurons per core, but it does not seem to have an effect. 

The number n_connections comes from 1156 * 512 * 4(number of synapses) and I just had to split between excitatory and inhibitory.  

Also I so the splitter functionality SplitterAbstractPopulationVertexNeuronsSynapses() would you mind giving me an overview of how it works and could it be used for this?

Thanks for your help,

Alfonso

[Andrew Rowley]

Hi,

 

In general, this error is referring to the number of connections from each source neuron that target neurons on each core.  On SpiNNaker this is kept as a list of up to 256 target neurons for each source neuron.  If there are more than 256 target neurons for at least one source neuron, you will see this error.  In your case, because you have created 4 connections for each source for each target (though I understand you have split these into excitatory and inhibitory), this is why you see the error.

 

Fortunately, the connectors are considered separately in the software and so you can add more connections than the limit.  Therefore you could instead create 4 FromListConnector instances, each with just one connection between each source and target (or 8 I suppose with 4 excitatory and 4 inhibitory).  This would then hopefully get rid of the error.

 

Andrew :)

 

From: spinnak...@googlegroups.com <spinnak...@googlegroups.com> On Behalf Of Alfonso Yamamoto
Sent: Wednesday, June 12, 2024 10:10 AM
To: SpiNNaker Users Group <spinnak...@googlegroups.com>
Subject: [SpiNNaker Mailing List] Too many synapses?

 

Hi,

I was trying to increment the number of synapses on my network.

See the attached photo for the setup.

 

Previously I was just using an AllToAllConnector() from the input layer to the hidden layer. That worked fine. Then I wanted to use a FromListConnector(), that would allow me to have multiple synapses between input neuron (SpikeSourceArray) and my model neuron. For instance, right now I would like to try to have four synapses; they can be either excitatory or inhibitory. 

 

But when I try to run my script I get the following:

I already tried to lower the number of neurons per core, but it does not seem to have an effect. 

The number n_connections comes from 1156 * 512 * 4(number of synapses) and I just had to split between excitatory and inhibitory.  

Also I so the splitter functionality SplitterAbstractPopulationVertexNeuronsSynapses() would you mind giving me an overview of how it works and could it be used for this?

 

Thanks for your help,

 

Alfonso

 

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