Strong scaling performance, Free benchmark, P100, 64M particles 
Performance in millions of particle-timesteps / second / node 
| Nodes | Kokkos/Cuda-1 (mpi) | Kokkos/Cuda-2 (mpi) | Kokkos/Cuda-4 (mpi) | |
| 1 | 224 (1) | 452 (2) | 865.2 (4) | |
| 2 | 221.3 (1) | 445.8 (2) | 854.7 (4) | |
| 4 | 218.4 (1) | 435.6 (2) | 819.4 (4) | |
| 8 | None | 418.4 (2) | 734.4 (4) | 
| 1 | mpirun -np 2 --npernode 1 --bind-to core spa_ride100_kokkos_cuda -sf kk -k on g 1 -pk kokkos reduction atomic comm threaded -v x 256 -v y 160 -v z 160 -v t 100 -in in.free.steps -log log.sparta.date=23Dec17.model=free.machine=ride100.pkg=kokkos_cuda.kind=strong.size=64M.node=2.mpi=1.gpu=1 | 
| 2 | mpirun -np 4 --npernode 1 --bind-to core spa_ride100_kokkos_cuda -sf kk -k on g 1 -pk kokkos reduction atomic comm threaded -v x 256 -v y 160 -v z 160 -v t 100 -in in.free.steps -log log.sparta.date=23Dec17.model=free.machine=ride100.pkg=kokkos_cuda.kind=strong.size=64M.node=4.mpi=1.gpu=1 | 
| 4 | mpirun -np 8 --npernode 1 --bind-to core spa_ride100_kokkos_cuda -sf kk -k on g 1 -pk kokkos reduction atomic comm threaded -v x 256 -v y 160 -v z 160 -v t 100 -in in.free.steps -log log.sparta.date=23Dec17.model=free.machine=ride100.pkg=kokkos_cuda.kind=strong.size=64M.node=8.mpi=1.gpu=1 | 
| 8 | None | 
| 1 | mpirun -np 2 --npersocket 1 --bind-to core spa_ride100_kokkos_cuda -sf kk -k on g 2 -pk kokkos reduction atomic comm threaded -v x 256 -v y 160 -v z 160 -v t 100 -in in.free.steps -log log.sparta.date=23Dec17.model=free.machine=ride100.pkg=kokkos_cuda.kind=strong.size=64M.node=1.mpi=2.gpu=2 | 
| 2 | mpirun -np 4 --npersocket 1 --bind-to core spa_ride100_kokkos_cuda -sf kk -k on g 2 -pk kokkos reduction atomic comm threaded -v x 256 -v y 160 -v z 160 -v t 100 -in in.free.steps -log log.sparta.date=23Dec17.model=free.machine=ride100.pkg=kokkos_cuda.kind=strong.size=64M.node=2.mpi=2.gpu=2 | 
| 4 | mpirun -np 8 --npersocket 1 --bind-to core spa_ride100_kokkos_cuda -sf kk -k on g 2 -pk kokkos reduction atomic comm threaded -v x 256 -v y 160 -v z 160 -v t 100 -in in.free.steps -log log.sparta.date=23Dec17.model=free.machine=ride100.pkg=kokkos_cuda.kind=strong.size=64M.node=4.mpi=2.gpu=2 | 
| 8 | mpirun -np 16 --npersocket 1 --bind-to core spa_ride100_kokkos_cuda -sf kk -k on g 2 -pk kokkos reduction atomic comm threaded -v x 256 -v y 160 -v z 160 -v t 100 -in in.free.steps -log log.sparta.date=23Dec17.model=free.machine=ride100.pkg=kokkos_cuda.kind=strong.size=64M.node=8.mpi=2.gpu=2 | 
| 1 | mpirun -np 4 --npersocket 2 --bind-to core spa_ride100_kokkos_cuda -sf kk -k on g 4 -pk kokkos reduction atomic comm threaded -v x 256 -v y 160 -v z 160 -v t 100 -in in.free.steps -log log.sparta.date=23Dec17.model=free.machine=ride100.pkg=kokkos_cuda.kind=strong.size=64M.node=1.mpi=4.gpu=4 | 
| 2 | mpirun -np 8 --npersocket 2 --bind-to core spa_ride100_kokkos_cuda -sf kk -k on g 4 -pk kokkos reduction atomic comm threaded -v x 256 -v y 160 -v z 160 -v t 100 -in in.free.steps -log log.sparta.date=23Dec17.model=free.machine=ride100.pkg=kokkos_cuda.kind=strong.size=64M.node=2.mpi=4.gpu=4 | 
| 4 | mpirun -np 16 --npersocket 2 --bind-to core spa_ride100_kokkos_cuda -sf kk -k on g 4 -pk kokkos reduction atomic comm threaded -v x 256 -v y 160 -v z 160 -v t 100 -in in.free.steps -log log.sparta.date=23Dec17.model=free.machine=ride100.pkg=kokkos_cuda.kind=strong.size=64M.node=4.mpi=4.gpu=4 | 
| 8 | mpirun -np 32 --npersocket 2 --bind-to core spa_ride100_kokkos_cuda -sf kk -k on g 4 -pk kokkos reduction atomic comm threaded -v x 256 -v y 160 -v z 160 -v t 100 -in in.free.steps -log log.sparta.date=23Dec17.model=free.machine=ride100.pkg=kokkos_cuda.kind=strong.size=64M.node=8.mpi=4.gpu=4 |