Unify handling of GMX_ENABLE_GPU_TIMING and GMX_DISABLE_GPU_TIMING

[alexxy/gromacs.git] / docs / user-guide / environment-variables.rst

diff --git a/docs/user-guide/environment-variables.rst b/docs/user-guide/environment-variables.rst
index 8d288eed43bda79949bcc8e2ed8e42662884a4f7..1f323174e1124da09523dbf792d20286fd844d23 100644 (file)
--- a/docs/user-guide/environment-variables.rst
+++ b/docs/user-guide/environment-variables.rst
@@ -22,9 +22,6 @@ you should consult your local documentation for details.
 
 Output Control
 --------------
-``GMX_CONSTRAINTVIR``
-        Print constraint virial and force virial energy terms.
-
 ``GMX_DUMP_NL``
         Neighbour list dump level; default 0.
 
@@ -85,8 +82,8 @@ Output Control
         files. Set to 0 for quiet operation.
 
 ``GMX_ENABLE_GPU_TIMING``
-        Enables GPU timings in the log file for CUDA. Note that CUDA timings
-        are incorrect with multiple streams, as happens with domain
+        Enables GPU timings in the log file for CUDA and SYCL. Note that CUDA
+        timings are incorrect with multiple streams, as happens with domain
         decomposition or with both non-bondeds and PME on the GPU (this is
         also the main reason why they are not turned on by default).
 
@@ -170,6 +167,10 @@ Performance and Run Control
         (for coordinate and force buffers) directly on GPU memory spaces, without the staging of data through CPU
         memory, where possible. 
 
+``GMX_GPU_SYCL_NO_SYNCHRONIZE``
+        disable synchronizations between different GPU streams in SYCL build, instead relying on SYCL runtime to
+        do scheduling based on data dependencies. Experimental.
+
 ``GMX_CYCLE_ALL``
         times all code during runs.  Incompatible with threads.
 
@@ -210,6 +211,7 @@ Performance and Run Control
 ``GMX_DISABLE_GPU_TIMING``
         timing of asynchronously executed GPU operations can have a
         non-negligible overhead with short step times. Disabling timing can improve performance in these cases.
+        Timings are disabled by default with CUDA and SYCL.
 
 ``GMX_DISABLE_GPU_DETECTION``
         when set, disables GPU detection even if :ref:`gmx mdrun` was compiled
@@ -396,10 +398,6 @@ Performance and Run Control
         by mdrun. Values should be between the pruning frequency value
         (1 for CPU and 2 for GPU) and :mdp:`nstlist` ``- 1``.
 
-``GMX_USE_TREEREDUCE``
-        use tree reduction for nbnxn force reduction. Potentially faster for large number of
-        OpenMP threads (if memory locality is important).
-
 .. _opencl-management:
 
 OpenCL management
@@ -426,6 +424,7 @@ compilation of OpenCL kernels, but they are also used in device selection.
 
 ``GMX_OCL_DISABLE_FASTMATH``
         Prevents the use of ``-cl-fast-relaxed-math`` compiler option.
+        Not: fast math is always disabled on Intel devices due to instability.
 
 ``GMX_OCL_DUMP_LOG``
         If defined, the OpenCL build log is always written to the
@@ -445,8 +444,8 @@ compilation of OpenCL kernels, but they are also used in device selection.
         ``GMX_OCL_NOGENCACHE``).
 
             - NVIDIA GPUs: PTX code is saved in the current directory
-             with the name ``device_name.ptx``
-           - AMD GPUs: ``.IL/.ISA`` files will be created for each OpenCL
+              with the name ``device_name.ptx``
+            - AMD GPUs: ``.IL/.ISA`` files will be created for each OpenCL
               kernel built.  For details about where these files are
               created check AMD documentation for ``-save-temps`` compiler
               option.
@@ -502,9 +501,6 @@ Analysis and Core Functions
         terminal residues (NXXX and CXXX) as :ref:`rtp` entries that are normally renamed. Setting
         this environment variable disables this renaming.
 
-``GMX_PATH_GZIP``
-        ``gunzip`` executable, used by :ref:`gmx wham`.
-
 ``GMX_FONT``
         name of X11 font used by :ref:`gmx view`.