Accel

Name AccelBenchmark
Section Execution::Accel
Type logical
Default no

If this variable is set to yes, Octopus will run some routines to benchmark the performance of the accelerator device.

Name AccelDevice
Section Execution::Accel
Type integer
Default 0

This variable selects the GPU that Octopus will use. You can specify a numerical id to select a specific device.

In case of MPI enabled runs devices are distributed in a round robin fashion, starting at this value.

Name AllowCPUonly
Section Execution::Accel
Type logical

In order to prevent waste of resources, the code will normally stop when the GPU is disabled due to incomplete implementations or incompatibilities. AllowCPUonly = yes overrides this and allows the code execution also in these cases.

Name DisableAccel
Section Execution::Accel
Type logical
Default yes

If Octopus was compiled with CUDA support, it will try to initialize and use an accelerator device. By setting this variable to yes you force Octopus not to use an accelerator even it is available.

Name GPUAwareMPI
Section Execution::Accel
Type logical

If Octopus was compiled with GPU support and MPI support and if the MPI implementation is GPU-aware (i.e., it supports communication using device pointers), this switch can be set to true to use the GPU-aware MPI features. The advantage of this approach is that it can do, e.g., peer-to-peer copies between devices without going through the host memory. The default is false, except when the configure switch –enable-cudampi is set, in which case this variable is set to true.

Name InitializeGPUBuffers
Section Execution::Accel
Type integer
Default no

Initialize new GPU buffers to zero on creation (use only for debugging, as it has a performance impact!).

Options:

• no:
  Do not initialize GPU buffers.
  
• yes:
  Initialize GPU buffers to zero.
  
• nan:
  Initialize GPU buffers to nan.