diff --git a/bench/KEPLER/README b/bench/KEPLER/README
index 1d643beeaa..eea12513f5 100644
--- a/bench/KEPLER/README
+++ b/bench/KEPLER/README
@@ -16,30 +16,37 @@ openmpi/1.8.1/intel/13.1.SP1.106/cuda/6.0.37.
 
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-You can of course build LAMMPS yourself with any of the accelerator
+You can, of course, build LAMMPS yourself with any of the accelerator
 packages for your platform.
 
 The build.py script will build LAMMPS for the various accelerlator
 packages using the Makefile.* files in this dir, which you can edit if
 necessary for your platform.  You must set the "lmpdir" variable at
 the top of build.py to the home directory of LAMMPS as installed on
-your system.  Then typing, for example,
+your system.  Note that the build.py script hardcodes the arch setting
+for the USER-CUDA package, which should be matched to the GPUs on your
+system, e.g. sm_35 for Kepler GPUs.  For the GPU package, this setting
+is in the Makefile.gpu.* files, as is the CUDA_HOME variable which
+should point to where NVIDIA Cuda software is installed on your
+system.
+
+Once the Makefiles are in place, then typing, for example,
 
 python build.py cpu gpu
 
-will build executables for the CPU (no accelerators), and 3 GPU
-variants (double, mixed, single precision).  See the list
-of possible targets at the top of the build.py script.
+will build executables for the CPU (no accelerators), and 3 variants
+(double, mixed, single precision) of the GPU package.  See the list of
+possible targets at the top of the build.py script.
 
-Note that the build.py script will un-install all packages in LAMMPS,
-then only install the ones needed for the benchmark.  The Makefile.*
-files in this dir are copied into lammps/src/MAKE, as a dummy
-Makefile.foo, so they will not conflict with makefiles that may
-already be there.  The build.py script also builds the auxiliary
-GPU and USER-CUDA library as needed.
+Note that the build.py script will un-install all packages in your
+LAMMPS directory, then only install the ones needed for the benchmark.
+The Makefile.* files in this dir are copied into lammps/src/MAKE, as a
+dummy Makefile.foo, so they will not conflict with makefiles that may
+already be there.  The build.py script also builds the auxiliary GPU
+and USER-CUDA library as needed.
 
-The various LAMMPS executables are copied into this directory
-when the build.py script finishes each build.
+LAMMPS executables that are generated by build.py are copied into this
+directory when the script finishes each build.
 
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