SST Elements

SST Element libraries contain components, subcomponents, modules, and other SST objects that can be used to build a simulation.

SST Community Libraries

The pages in this area describe the libraries available from the SST project. Many other libraries are available, check out the community page.

SST Project Libraries

Most SST-provided element libraries are located in the sst-elements repository, though a few are in separate repositories. The libraries range from early-stage models with limited functionality to those that are mature and extensively tested. In addition, we categorize elements by development activity and planned trajectory ("development path").

SST elements are categorized according to maturity and development path.

Maturity

	Maturity	Reliability	Testing	Documentation
Early Development (1)	An element in its initial stages of development. "Alpha" quality.	May be unreliable. The APIs and behavior of the element may change and the element should not be considered stable yet. Configurations outside those tested may fail to work.	None required. Tests may produce unreliable and/or unreproducible results.	None required.
Prototype (2)	The element's basic functionality is in place, but many features are still being developed. The element is usable within tested configurations but may not work outside of those. "Beta" quality.	Somewhat reliable. APIs and implementations may change suddenly as development progresses. Bugs may be encountered outside of tested configurations.	Required. Passes basic functionality testing. Builds reliably as part of overnight project builds.	Required. Documentation may be limited to a statement of the element's use and behavior.
Mature (3)	The element's major capabilities are stable, reliable, and reasonably well-tested although performance enhancements, validation, and new features may be on-going.	Reliable. The element's major features are stable, tested, and in some cases, validated. Major and/or breaking changes are communicated to users in advance (e.g., deprecation warnings, release notes, etc.).	Required. Has undergone substantial capability testing. Builds reliably as part of overnight project builds.	Required. More extensive than that of prototype elements.

Development Path

In addition to a maturity level, elements belong to one of the following development paths.  

Experimental: A unique, "one-off" or experimental implementation that is not necessarily intended to be part of SST long-term. No elements in other development paths may rely on experimental elements. These elements are considered "unsupported".  

Active: An element that is actively being maintained, enhanced, and developed.  

Maintenance: An element that is not currently under active development but is still maintained and tested regularly. Occasional feature updates and bug fixes will be made to ensure the element continues to function. This does not imply end-of-life.  

Deprecated: An element that is end-of-life. Once deprecated, an element is subject to removal in future releases.

sst-info

All Element libraries, whether provided via the SST repos or from the community, export certain Element Library Information (ELI) that can be queried at the command line using the sst-info utility. This information includes a basic description of each element (i.e., component, subcomponent, module, etc.) within the library as well the parameters, statistics, and ports available for the element. Elements that implement interfaces (e.g., subcomponents, modules, etc.) also declare which interface they implement. The documentation here supplements sst-info's basic information and provides context, implementation details, and configuration hints.

SST-Elements Repository Structure

The root directory of sst-elements contains a number of subdirectories as well as a brief README, License, and contributor information. The element source code lies in the sst-elements/src/sst/elements subdirectory. Each library has its own directory in this location. Generally, it is the convention for libraries to include their set of tests in a tests subdirectory.

SST Elements

Elements range from experimental to mature. Most of the elements below reside in the sst-elements repository, but a few are in standalone repositories. All are available via the sstsimulator repositories while only the "released" libraries are available from the release tarballs.

Examples

Element Name	Maturity	Dev Path	Last Release	Description
simpleElementExample	3	Active	15.0	Examples for building, running, parameterizing, etc. simulations and elements
simpleExternalElement	3	Active	15.0	Example of an element library external to the sst-elements repository
simpleSimulation	3	Maintenance	12.1	Example simulation components that simulate cars going through a carwash

Network Endpoints

These models are generally used to drive networks at system scales where detailed cycle-level processor modeling become prohibitively time-consuming.

Element Name	Maturity	Dev Path	Last Release	Description
ember	3	Active	15.0	Communication motifs for network simulations
firefly	3	Active	15.0	Low-level communication protocol for use with system network simulations
hermes	3	Active	15.0	Interface to message passing functions for system network simulations
iris	1	Active	15.0	Communication middleware targeting the Mercury simulation environment
macro	3	Maintenance	15.0	Simulation of coarse-grain distributed memory applications
mask-mpi	3	Active	15.0	An MPI implementation which targets the SUMI (see Iris) interface
mercury	1	Active	15.0	Support for workload/application models
thornhill	1	Maintenance	15.0	Support library for detailed endpoint models in Ember
zodiac	1	Maintenance	15.0	Trace-based endpoints for network simulation

Networks

Element Name	Maturity	Dev Path	Last Release	Description
kingsley	2	Active	15.0	Simulates a mesh network-on-chip
merlin	3	Active	15.0	Router model with flexible topology modules to simulate networks.
shogun	2	Active	15.0	Provides a simple crossbar model

Processors and Accelerators

Element Name	Maturity	Dev Path	Last Release	Description
ariel	3	Active	15.0	Dynamic trace-based model leveraging PIN to execute x86 binaries
balar	2	Active	15.0	GPU component based on GPGPU-Sim
gensa	1	Active	15.0	Neuromorphic processor
golem	2	Active	15.0	Simulation of array-based in situ computing components with optional integration with CrossSim
juno	2	Maintenance	15.0	Example pipeline processor model with a custom ISA
llyr	1	Active	Never	A spatial compute accelerator model
miranda	3	Active	15.0	Processor driven by a state machine to generate memory instructions
prospero	2	Active	15.0	Processor that reads a trace from file
serrano	1	Experimental	Never	Coarse-grain reconfigurable processor model
vanadis	2	Active	15.0	Core pipeline model supporting RISC-V and MIPS

Cache and Memory System

Element Name	Maturity	Dev Path	Last Release	Description
cacheTracer	1	Maintenance	15.0	Intercepts cache accesses for observation
cassini	2	Active	15.0	Prefetchers and other memory system plug-in modules
cramSim	2	Maintenance	15.0	Memory model from IBM - DDR, HBM
memHierarchy	3	Active	15.0	Memory system components including caches, directories, and memory controllers and models
messier	2	Active	15.0	Provides a detailed model for NVM-based DIMMs with high-end internal controller
mmu	1	Active	15.0	A basic TLB/MMU implementation that works with Vanadis
opal	1	Active	Never	Memory allocation support for multi-node simulations using Ariel
rdmaNic	1	Active	15.0	Facilitates RDMA in conjunction with Vanadis
samba	2	Maintenance	15.0	A detailed memory management unit (MMU) model
vaultsim	3	Maintenance	15.0	Models a vaulted memory architecture

Other/Miscellaneous

Element Name	Maturity	Dev Path	Last Release	Description
osseous	1	Active	15.0	Supports generation of SST components from RTL via Essent