my server dell c4140 with 4 v100 sxm2 inside.
then i found the nvlink is not effect, and i want to know how to enable it.
C:>nvidia-smi nvlink -c
GPU 0: Tesla V100-SXM2-16GB (UUID: GPU-fde8b6eb-3fcc-6062-d0df-ec38368d04c1)
Link 0, P2P is supported: true
Link 0, Access to system memory supported: true
Link 0, P2P atomics supported: true
Link 0, System memory atomics supported: true
Link 0, SLI is supported: false
Link 0, Link is supported: false
Link 1, P2P is supported: true
Link 1, Access to system memory supported: true
Link 1, P2P atomics supported: true
Link 1, System memory atomics supported: true
Link 1, SLI is supported: false
Link 1, Link is supported: false
Link 2, P2P is supported: true
Link 2, Access to system memory supported: true
Link 2, P2P atomics supported: true
Link 2, System memory atomics supported: true
Link 2, SLI is supported: false
Link 2, Link is supported: false
Link 3, P2P is supported: true
Link 3, Access to system memory supported: true
Link 3, P2P atomics supported: true
Link 3, System memory atomics supported: true
Link 3, SLI is supported: false
Link 3, Link is supported: false
Link 4, P2P is supported: true
Link 4, Access to system memory supported: true
Link 4, P2P atomics supported: true
Link 4, System memory atomics supported: true
Link 4, SLI is supported: false
Link 4, Link is supported: false
Link 5, P2P is supported: true
Link 5, Access to system memory supported: true
Link 5, P2P atomics supported: true
Link 5, System memory atomics supported: true
Link 5, SLI is supported: false
Link 5, Link is supported: false
GPU 1: Tesla V100-SXM2-16GB (UUID: GPU-a1d45500-e099-7229-fe4e-21f96bab285d)
Link 0, P2P is supported: true
Link 0, Access to system memory supported: true
Link 0, P2P atomics supported: true
Link 0, System memory atomics supported: true
Link 0, SLI is supported: false
Link 0, Link is supported: false
Link 1, P2P is supported: true
Link 1, Access to system memory supported: true
Link 1, P2P atomics supported: true
Link 1, System memory atomics supported: true
Link 1, SLI is supported: false
Link 1, Link is supported: false
Link 2, P2P is supported: true
Link 2, Access to system memory supported: true
Link 2, P2P atomics supported: true
Link 2, System memory atomics supported: true
Link 2, SLI is supported: false
Link 2, Link is supported: false
Link 3, P2P is supported: true
Link 3, Access to system memory supported: true
Link 3, P2P atomics supported: true
Link 3, System memory atomics supported: true
Link 3, SLI is supported: false
Link 3, Link is supported: false
Link 4, P2P is supported: true
Link 4, Access to system memory supported: true
Link 4, P2P atomics supported: true
Link 4, System memory atomics supported: true
Link 4, SLI is supported: false
Link 4, Link is supported: false
Link 5, P2P is supported: true
Link 5, Access to system memory supported: true
Link 5, P2P atomics supported: true
Link 5, System memory atomics supported: true
Link 5, SLI is supported: false
Link 5, Link is supported: false
GPU 2: Tesla V100-SXM2-16GB (UUID: GPU-3220fdb4-507a-d838-3219-44187789d766)
Link 0, P2P is supported: true
Link 0, Access to system memory supported: true
Link 0, P2P atomics supported: true
Link 0, System memory atomics supported: true
Link 0, SLI is supported: false
Link 0, Link is supported: false
Link 1, P2P is supported: true
Link 1, Access to system memory supported: true
Link 1, P2P atomics supported: true
Link 1, System memory atomics supported: true
Link 1, SLI is supported: false
Link 1, Link is supported: false
Link 2, P2P is supported: true
Link 2, Access to system memory supported: true
Link 2, P2P atomics supported: true
Link 2, System memory atomics supported: true
Link 2, SLI is supported: false
Link 2, Link is supported: false
Link 3, P2P is supported: true
Link 3, Access to system memory supported: true
Link 3, P2P atomics supported: true
Link 3, System memory atomics supported: true
Link 3, SLI is supported: false
Link 3, Link is supported: false
Link 4, P2P is supported: true
Link 4, Access to system memory supported: true
Link 4, P2P atomics supported: true
Link 4, System memory atomics supported: true
Link 4, SLI is supported: false
Link 4, Link is supported: false
Link 5, P2P is supported: true
Link 5, Access to system memory supported: true
Link 5, P2P atomics supported: true
Link 5, System memory atomics supported: true
Link 5, SLI is supported: false
Link 5, Link is supported: false
GPU 3: Tesla V100-SXM2-16GB (UUID: GPU-f5a6ea19-ce0f-bd08-d367-3ecbb135ff3b)
Link 0, P2P is supported: true
Link 0, Access to system memory supported: true
Link 0, P2P atomics supported: true
Link 0, System memory atomics supported: true
Link 0, SLI is supported: false
Link 0, Link is supported: false
Link 1, P2P is supported: true
Link 1, Access to system memory supported: true
Link 1, P2P atomics supported: true
Link 1, System memory atomics supported: true
Link 1, SLI is supported: false
Link 1, Link is supported: false
Link 2, P2P is supported: true
Link 2, Access to system memory supported: true
Link 2, P2P atomics supported: true
Link 2, System memory atomics supported: true
Link 2, SLI is supported: false
Link 2, Link is supported: false
Link 3, P2P is supported: true
Link 3, Access to system memory supported: true
Link 3, P2P atomics supported: true
Link 3, System memory atomics supported: true
Link 3, SLI is supported: false
Link 3, Link is supported: false
Link 4, P2P is supported: true
Link 4, Access to system memory supported: true
Link 4, P2P atomics supported: true
Link 4, System memory atomics supported: true
Link 4, SLI is supported: false
Link 4, Link is supported: false
Link 5, P2P is supported: true
Link 5, Access to system memory supported: true
Link 5, P2P atomics supported: true
Link 5, System memory atomics supported: true
Link 5, SLI is supported: false
Link 5, Link is supported: false