diff --git a/2.ami_and_containers/containers/pytorch/0.nvcr-pytorch-aws.dockerfile b/2.ami_and_containers/containers/pytorch/0.nvcr-pytorch-aws.dockerfile
index 49ab8c03..ff229aa7 100644
--- a/2.ami_and_containers/containers/pytorch/0.nvcr-pytorch-aws.dockerfile
+++ b/2.ami_and_containers/containers/pytorch/0.nvcr-pytorch-aws.dockerfile
@@ -3,7 +3,8 @@
 
 ####################################################################################################
 # This is a sample Dockerfile, with optional stanzas. Please read through this Dockerfile,
-# understand what it does, then create your own Dockerfile.
+# understand what it does, then create your own Dockerfile. Software versions are provided for
+# illustration only.
 #
 # Sample build instructions:
 #
@@ -19,13 +20,13 @@
 #     # Load image to local docker registry -> on head node, or new compute/build node.
 #     docker load < /fsx/nvidia-pt-od__latest.tar
 ####################################################################################################
-FROM nvcr.io/nvidia/pytorch:23.12-py3
+FROM nvcr.io/nvidia/pytorch:24.03-py3
 ENV DEBIAN_FRONTEND=noninteractive
 
 # The three must-be-built packages.
 # Efa-installer>=1.29.1 required for nccl>=2.19.0 to avoid libfabric NCCL error.
-ENV EFA_INSTALLER_VERSION=1.30.0
-ENV AWS_OFI_NCCL_VERSION=1.8.1-aws
+ENV EFA_INSTALLER_VERSION=1.32.0
+ENV AWS_OFI_NCCL_VERSION=1.9.1-aws
 ENV NCCL_TESTS_VERSION=master
 
 ## Uncomment below when this Dockerfile builds a container image with efa-installer<1.29.1 and
@@ -88,10 +89,13 @@ ENV PATH=/opt/amazon/efa/bin:/opt/amazon/openmpi/bin:$PATH
 # [CUSTOM_NCCL_OPTION_1] Uncomment below stanza to install another NCCL version using the official
 # binaries.
 #
+# Please consult https://docs.nvidia.com/deeplearning/frameworks/pytorch-release-notes/index.html to
+# find out the prebuilt nccl version in the parent image.
+#
 # NCCL EFA plugin (aws-ofi-nccl) depends on mpi, hence we must rebuild openmpi before building the
 # aws-ofi-ccnl.
 ####################################################################################################
-#ENV NCCL_VERSION=2.19.3-1
+#ENV NCCL_VERSION=2.21.5-1
 #RUN cd /opt && \
 #    wget https://developer.download.nvidia.com/compute/cuda/repos/ubuntu2004/x86_64/cuda-keyring_1.0-1_all.deb && \
 #    dpkg -i cuda-keyring_1.0-1_all.deb && \
@@ -101,17 +105,21 @@ ENV PATH=/opt/amazon/efa/bin:/opt/amazon/openmpi/bin:$PATH
 
 
 ####################################################################################################
-# [CUSTOM_NCCL_OPTION_2] Install NCCL from source to the same location as the built-in ones. The
-# benefits of installing to the same location as the built-in version are:
+# [CUSTOM_NCCL_OPTION_2] Install NCCL from source to the same location as the built-in ones.
+#
+# Please consult https://docs.nvidia.com/deeplearning/frameworks/pytorch-release-notes/index.html to
+# find out the prebuilt nccl version in the parent image.
+#
+# Installation mechanics:
 #
-# 1. There's only ever a single libnccl version offered by this image, preventing application from
-#    mistakenly chooses a wrong version.
-# 2. No longer needing extra settings for LD_LIBRARY_PATH or LD_PRELOAD.
+# 1. Remove pre-installed nccl to ensure there's only ever a single libnccl version offered by this
+#    image, preventing application from mistakenly chooses a wrong version.
+# 2. Install to default location, so no more extra settings for LD_LIBRARY_PATH or LD_PRELOAD.
 #
 # NCCL EFA plugin (aws-ofi-nccl) depends on mpi, hence we must rebuild openmpi before building the
 # aws-ofi-ccnl.
 ####################################################################################################
-ENV NCCL_VERSION=2.19.3-1
+ENV NCCL_VERSION=2.21.5-1
 RUN apt-get remove -y libnccl2 libnccl-dev \
    && cd /tmp \
    && git clone https://github.com/NVIDIA/nccl.git -b v${NCCL_VERSION} \
diff --git a/2.ami_and_containers/containers/pytorch/README.md b/2.ami_and_containers/containers/pytorch/README.md
index 79d65795..f0fc5c14 100644
--- a/2.ami_and_containers/containers/pytorch/README.md
+++ b/2.ami_and_containers/containers/pytorch/README.md
@@ -13,6 +13,10 @@ With that said, feel free to explore the example. Happy coding, and experimentin
 
 ## 1. Essential software
 
+Please note that software versions in the template are provided for illustration only. For
+well-tested combinations, please refer to the various Dockerfile files under `3.test_cases/` and
+`4.validation_and_observability/0.nccl_tests/`.
+
 In principle, the reference `Dockerfile` does the following:
 
 - Provide PyTorch built for NVidia CUDA devices, by using a recent NVidia PyTorch image as the