CHANGES
What's new in ChaNGa 3.4 (Since 3.3)
===============================================================================
General changes:
- Move to Charm version 6.9.0
This move requires the use of a C++11 compliant compiler. For GCC this is
version 4.8.1 or later.
- C++ file rename to ".cpp".
- Improved configure/make system.
Physics Changes:
- Molecular Hydrogen physics for star formation and feedback
- Metal cooling
- Protoplanetary disk cooling
- Superbubble feedback
- Early UV feedback
- Supermassive Black Hole formation and feedback
- Self-Interacting Dark Matter
- Gas splitting
Parallel performance changes:
- Local tree walk can be performed on the GPU.
- Better memory use in GPU code.
- More even distribution of work across processors when multistepping
Code cleanup:
- Refactored Main timestepping routine.
- Bug fixes.
===============================================================================
What's new in ChaNGa 3.3 (Since 3.2)
===============================================================================
General changes:
- Move to Charm version 6.8.0
Physics Changes: (Many from Wadsley, Keller and Quinn, 2017)
- Adaptive artificial visoscity
- Smagorinsky diffusion
- Thermal diffusion
- Saitoh timestepping
- New SPH Kernels: Wendland, M6
- Geometric density averaged SPH forces.
- External gravitational potentials: constant g, patch of a disk, central body
- AGORA (2016) feedback model
- Damping force for glass creation
Parallel performance changes:
- Working GPU implementation
- Single precision floating point gravity
- SPH neighbor search improvements
===============================================================================
What's new in ChaNGa 3.2 (Since 3.1)
===============================================================================
General changes:
- Move to Charm version 6.7.1
- Restart from "tipsy binary" files.
- More flexible "dumpframe" movie making.
- Complete handling of > 2 billion particles, including 64 bit iOrders in
the starlog file.
Physics Changes:
- Grackle cooling module.
- Jeans length pressure floor.
- Improved "beta cooling" for disks.
Parallel performance changes:
- More efficient smoothing cache.
- Better scaling for tree build.
- Better bookkeeping for multistep load balancing.
===============================================================================
What's new in ChaNGa 3.1 (Since 3.0)
===============================================================================
General changes:
- Support for greater than 2 billion particles.
- Support for NChilada file format.
Hardware support changes:
- Remove support for CELL processor (Playstation).
- AVX instruction support.
Parallel performance changes:
- SMP load balancing using the Charm++ Ck_Loop Library
- More efficient parallel I/O using the Charm++ CkIO library.
- Faster domain decomposition.
- New load balancers
- Better multistep load bookkeeping
- HierarchicalLB for large core counts
- MultistepNodeLB_notopo for node-based load balancing.
===============================================================================
What's new in ChaNGa 3.0 (Since 2.0)
===============================================================================
Physics Changes:
- Gas Cooling: primordial hydrogen and helium, planetary disk cooling with
cooling time proportional to orbital time.
- More efficient thermal energy equation solver.
- Star formation and feedback
- Timestepping fixes
-------------------------------------------------------------------------------
Hardware support changes:
- SMP aware: cores on an SMP node share tree data
- Use of 128 key type for deeper trees: enable with -DBIGKEYS
-------------------------------------------------------------------------------
Parallel Infrastructure Changes:
- Improved parallel treebuild
- Improved neighbor search algorithms
- Improved spatially aware load balancers
===============================================================================
What's new in ChaNGa 2.0 (Since 1.0)
===============================================================================
Physics Changes:
- Smooth Particle Hydrodynamics is now implemented.
- Hexadecapole expansions for the gravity calculation.
- Physical gravitational softening lengths for comoving simulations.
- Gravitational timestepping option.
- Non-cubical periodic boundary conditions.
- Adiabatically grow particle masses for equilibrium initial conditions.
-------------------------------------------------------------------------------
Output Changes:
- Output of movie files is available.
- Realtime visualization via liveViz is implemented.
- Output at specific redshifts or times.
-------------------------------------------------------------------------------
Hardware support changes:
- Support for CUDA.
- SSE2 implementation of force calculations.
- Better detection of 64 bit integer type.
-------------------------------------------------------------------------------
Parallel Infrastructure Changes:
- Multistep-aware load balancer.
- Rewrite of inter node caching to use the Charm++ Cache framework.
- Refactor of treewalking for easier support for new types of treewalks.
- Checkpointing using the Charm run time system.
- Overlapping treewalks.