Environment variables

The rocBLAS environment variables are collected in the following tables.

Environment variable	Default value	Links	Value
ROCBLAS_USE_HIPBLASLT Provides manual control over which GEMM backend is used.	Unset by default.	Control the GEMM backend	Unset: GEMM backend is automatically selected. 0: Tensile is always used as the GEMM backend. 1: hipBLASLt is preferred as the GEMM backend, but will fallback to Tensile on problems for which hipBLASLt does not provide a solution or when errors are encountered using the hipBLASLt backend.
ROCBLAS_USE_HIPBLASLT_BATCHED Manual control to selectively disable the use of hipBlasLt only for the batched GEMMs. ROCBLAS_USE_HIPBLASLT=0 disables the ROCBLAS_USE_HIPBLASLT_BATCHED variable, because hipBlasLt would not be enabled.	1	Control the GEMM backend	Unset: GEMM batched default backend. 0: Tensile is always used as the GEMM batched backend. 1: hipBLASLt will be used as the GEMM batched backend when applicable, but will fallback to Tensile on problems for which hipBLASLt does not provide a solution or when errors are encountered using the hipBLASLt backend.
ROCBLAS_DEVICE_MEMORY_SIZE Sets how much memory to preallocate.	Unset by default.	Preallocate memory	0 or unset: Lets rocBLAS manage the device memory. Bigger than 0: Sets the default handle device memory size to the specified size (in bytes).
ROCBLAS_DEFAULT_ATOMICS_MODE Sets the default atomics mode during the creation of rocblas_handle.	Unset by default.	Atomic operations	0: Sets the default to rocblas_atomics_not_allowed 1: Sets the default to rocblas_atomics_allowed
ROCBLAS_STREAM_ORDER_ALLOC Allows memory allocation and deallocation to be stream ordered.	0	Device memory allocation	0: Disable 1: Enable
ROCBLAS_BENCH_STREAM_SYNC Benchmark timing based on hipStreamSynchronize, otherwise uses default hipEvent_t based timing.	0	rocblas-bench timing	0: Disable 1: Enable

Logging environment variables

The logging environment variables in rocBLAS are collected in the following table. For information on how to use these variables, see rocBLAS logging.

Environment variable	Value
ROCBLAS_LAYER A bit mask to control the different types of logging.	ROCBLAS_LAYER == 0: Logging is disabled. ROCBLAS_LAYER & 1 == 1: Trace logging is enabled. ROCBLAS_LAYER & 2 == 1: Bench logging is enabled. ROCBLAS_LAYER & 4 == 1: Profile logging is enabled. ROCBLAS_LAYER & 8 == 1: Internal API logging is enabled.
ROCBLAS_LOG_PATH Sets the full path for logging.	Example: $PWD/logging.txt
ROCBLAS_LOG_TRACE_PATH Specifies the full path for trace logging. If this environment variable is set, the ROCBLAS_LOG_PATH environment variable is ignored for trace logs.	Example: $PWD/trace_logging.txt
ROCBLAS_LOG_BENCH_PATH Specifies the full path for bench logging. If this environment variable is set, the ROCBLAS_LOG_PATH environment variable is ignored for bench logs.	Example: $PWD/bench_logging.txt
ROCBLAS_LOG_PROFILE_PATH Specifies the full path for profile logging. If this environment variable is set, the ROCBLAS_LOG_PATH environment variable is ignored for profile logs.	Example: $PWD/profile_logging.txt