updating introductory material

00_introToAlcf/00_computeSystems.md

@@ -1,43 +1,83 @@
-# Argonne Leadership Computing Facility (ALCF) Overview
-[Overview of ALCF](img/ALCF-AITraining2021_dist.pdf)
+# What is a Supercomputer?
 
-# Computing System Overview
+Argonne hosts DOE supercomputers for use by research scientists in need of large computational resources. Supercomputers are composed of many computing _nodes_ (1 _node_ = 1 physical computer) that are connected by a high-speed communications network so that groups of nodes can share information quickly, effectively operating together as a larger computer.
 
-[Video presentation of our System Introduction](https://www.alcf.anl.gov/support-center/training-assets/getting-started-theta)
+# A Compute Node
 
-## Theta
+If you look inside your Desktop or Laptop you'll find these parts:
+
+![parts](img/computer-parts-diagram.png)
+
+A computing node of a supercomputer is very similar, each has simliar parts, but it is designed as a single unit that can be inserted and removed from large closet-sized racks with many others:
+
+![blade](img/computer_blade.jpg)
+
+In large supercomputers multiple computer processors (CPUs) and/or graphics processors (GPUs) are combined into a single node. It has a CPU on which the local operating system runs. It has local memory for running software. It may have GPUs for doing intensive calculations. Each node has a high-speed network connection that allows it to communicate with other nodes and to a large shared filesystem.
+
+# Cluster/HPC Computing Hardware Setup
+
+![Hardware](img/supercomputer_diagram.png)
+
+Large computer systems typically have _worker_ nodes and _login_ nodes. _login_ nodes are the nodes on which every user arrives when they login to the system. _login_ nodes should not be used for computation, but for compiling code, writing/editing code, and launching _jobs_ on the system. A _job_ is the application that will be launched on the _worker_ nodes of the supercomputer.
+
+# Supercomputers are Big!
+
+These supercomputers occupy a lot of space in the ACLF data center. Here is our staff at the time (2019) in front of [Mira](https://en.wikipedia.org/wiki/Mira_(supercomputer)), an IBM supercomputer, that debuted as the third fastest supercomputer in the world in 2012.
+
+![Staff-Mira](img/mira_staff.jpg)
+
+
+# ALCF Computing System Overview
+
+## [Theta](https://www.alcf.anl.gov/alcf-resources/theta)
 ![Theta](https://www.alcf.anl.gov/sites/default/files/styles/965x543/public/2019-10/09_ALCF-Theta_111016_rgb.jpg?itok=lcvZKE6k)
 
+The decals are stickers attached to the front of the computer _racks_ (closet sized). If you look inside a single closet you will see rows of computer _nodes_. Notice that there are repetitive rows inside the racks. These machines are made for _nodes_ to be replaced if needed.
+
+![Theta-nodes](img/theta1.jpg)
+
 Theta is an 11.7-petaflops supercomputer based on Intel processors and interconnect technology, an advanced memory architecture, and a Lustre-based parallel file system, all integrated by Cray’s HPC software stack.
 
 Theta Machine Specs
-* Architecture:  Intel-Cray XC40
 * Speed: 11.7 petaflops
-* Processor per node: 64-core, 1.3-GHz Intel Xeon Phi 7230
-* Nodes: 4,392
-* Cores: 281,088
-* Memory: 843 TB (192GB / node)
-* High-bandwidth memory: 70 TB (16GB / node)
-* Interconnect: Aries network with Dragonfly topology
-* Racks: 24
-
-## ThetaGPU
+* Each Node has:
+  * one 64-core Intel Xeon Phi (7230) CPU running at 1.3-GHz
+  * 192GB of DDR4 memory
+  * 16GB of high-bandwidth memory
+* 4,392 Total nodes installed in 24 Racks
+* High-speed Network Tech: Aries network with Dragonfly topology
+
+## [ThetaGPU](https://www.alcf.anl.gov/alcf-resources/theta)
+
+Inside ThetaGPU, you'll also see repetition, though NVidia placed these fancy plates over the hardware so you only see their logo. However, each plate covers 1 computer _node_.
+
+ ThetaGPU Racks | ThetaGPU Inside
+ --- | ---
+![ThetaGPU](img/thetagpu1.jpg) | ![ThetaGPU](img/thetagpu2.jpg)
+
 ThetaGPU is an NVIDIA DGX A100-based system. The DGX A100 comprises eight NVIDIA A100 GPUs that provide a total of 320 gigabytes of memory for training AI datasets, as well as high-speed NVIDIA Mellanox ConnectX-6 network interfaces.
 
 ThetaGPU Machine Specs
-* Architecture: NVIDIA DGX A100
 * Speed: 3.9 petaflops
-* Processors: AMD EPYC 7742
-* Nodes: 24
-* DDR4 Memory: 24 TB
-* GPU Memory: 7,680 GB
-* Racks: 7
+* Each Node has:
+  * 8 NVIDIA (A100) GPUs each with 40GB onboard memory
+  * 2 AMD EPYC (7742) CPUs
+  * 1 TB DDR4 Memory
+* 24 Total Nodes installed in 7 Racks
 
+## [Polaris](https://www.alcf.anl.gov/polaris)
 
-# Cluster/HPC Computing Hardware Setup
+![Polaris](img/polaris.jpg)
 
-![Hardware](img/supercomputer_diagram.png)
+The inside of Polaris again shows the _nodes_ stacked up in a closet.
+
+![Polaris-rack](img/polaris1.jpg)
 
-In large supercomputers, like Theta, you combine multiple computer processors (CPUs) and/or graphics processors (GPUs) into a single _node_. A _node_ is like your desktop computer. It has a CPU on which the local operating system runs. It has local memory for running software. It may have GPUs for doing intensive calculations. Each node has a high-speed network connection that allows it to communicate with other nodes and to a large shared filesystem.
+Polaris is an NVIDIA A100-based system.
 
-Large systems typically have _worker_ nodes and _login_ nodes. _login_ nodes are the nodes on which every user arrives when they login to the system. _login_ nodes should not be used for computation, but for compiling code, writing/editing code, and launching _jobs_ on the system. A _job_ is the application that will be launched on the _worker_ nodes of the supercomputer.
+Polaris Machine Specs
+* Speed: 44 petaflops
+* Each Node has:
+  * 4 NVIDIA (A100) GPUs
+  * 1 AMD EPYC (Milan) CPUs
+* ~560 Total Nodes