SUPS

{{Short description|Measure of neuronal network performance}}

In computational neuroscience, SUPS (for Synaptic Updates Per Second) or formerly CUPS (Connections Updates Per Second) is a measure of a neuronal network performance, useful in fields of neuroscience, cognitive science, artificial intelligence, and computer science.

Computing

For a processor or computer designed to simulate a neural network SUPS is measured as the product of simulated neurons N and average connectivity c(synapses) per neuron per second:

SUPS = c \times N

Depending on the type of simulation it is usually equal to the total number of synapses simulated.

In an "asynchronous" dynamic simulation if a neuron spikes at \upsilon Hz, the average rate of synaptic updates provoked by the activity of that neuron is \upsilon cN. In a synchronous simulation with step \Delta t the number of synaptic updates per second would be \frac{cN}{\Delta t}. As \Delta t has to be chosen much smaller than the average interval between two successive afferent spikes, which implies \Delta t < \frac{1}{\upsilon N}, giving an average of synaptic updates equal to \upsilon c N^2. Therefore, spike-driven synaptic dynamics leads to a linear scaling of computational complexity O(N) per neuron, compared with the O(N2) in the "synchronous" case.{{cite book

|author1=Maurizio Mattia |author2=Paolo Del Giudice |title=Icann 98 |year = 1998

|pages=1045–1050

|doi = 10.1007/978-1-4471-1599-1_164 |title-link=spiking neuron |chapter=Asynchronous simulation of large networks of spiking neurons and dynamical synapses |series=Perspectives in Neural Computing |isbn=978-3-540-76263-8 |citeseerx=10.1.1.56.272 }}

Records

Developed in the 1980s Adaptive Solutions' CNAPS-1064 Digital Parallel Processor chip is a full neural network (NNW). It was designed as a coprocessor to a host and has 64 sub-processors arranged in a 1D array and operating in a SIMD mode. Each sub-processor can emulate one or more neurons and multiple chips can be grouped together. At 25 MHz it is capable of 1.28 GMAC.[https://web.archive.org/web/20170706121300/ftp://ftp.cs.umass.edu/pub/osl/papers/uPSurvey-TR-95-42.ps.Z Real-Time Computing: Implications for General Microprocessors] Chip Weems, Steve Dropsho

After the presentation of the RN-100 (12 MHz) single neuron chip at Seattle 1991 Ricoh developed the multi-neuron chip RN-200. It had 16 neurons and 16 synapses per neuron. The chip has on-chip learning ability using a proprietary backdrop algorithm. It came in a 257-pin PGA encapsulation and drew 3.0 W at a maximum. It was capable of 3 GCPS (1 GCPS at 32 MHz).

{{cite book

|author1=L. Almeida |author2=Luis B. Almeida |author3=S. Boverie |year = 2003

|title = Intelligent Components and Instruments For Control Applications 2003 (SICICA 2003)

|publisher=Elsevier |url = https://books.google.com/books?id=pDFdub32IdYC |isbn=9780080440101 }}

In 1991–97, Siemens developed the MA-16 chip, SYNAPSE-1 and SYNAPSE-3 Neurocomputer. The MA-16 was a fast matrix-matrix multiplier that can be combined to form systolic arrays. It could process 4 patterns of 16 elements each (16-bit), with 16 neuron values (16-bit) at a rate of 800 MMAC or 400 MCPS at 50 MHz. The SYNAPSE3-PC PCI card contained 2 MA-16 with a peak performance of 2560 MOPS (1.28 GMAC); 7160 MOPS (3.58 GMAC) when using three boards.[http://neuralnets.web.cern.ch/NeuralNets/nnwinhephard.html Neural Network Hardware] Clark S. Lindsey, Bruce Denby, Thomas Lindblad, 1998

In 2013, the K computer was used to simulate a neural network of 1.73 billion neurons with a total of 10.4 trillion synapses (1% of the human brain). The simulation ran for 40 minutes to simulate 1 s of brain activity at a normal activity level (4.4 on average). The simulation required 1 Petabyte of storage.[http://www.cnet.com/news/fujitsu-supercomputer-simulates-1-second-of-brain-activity/ Fujitsu supercomputer simulates 1 second of brain activity] Tim Hornyak, CNET, August 5, 2013

See also

References