I am doing a research for my paper work on supercomputer subject, specifically for Tianhe-2. So i was reading a report from a professor Jack Dongarra and he mentions the CPM and APM halves of the board: "The compute board has two compute nodes and is composed of two half’s the CPM and the APM halves.The CPM portion of the compute board contains the 4 Ivy Bridge processors, memory, and 1 Xeon Phi board and the CPM half contains the 5 Xeon Phi boards".
So the first thing i have problem with is a compute, as a term, because i don't know how to translate compute board, if a have Xeon Phi boards on that compute board... O.o? The 2nd thing is about CPM and APM. What are CPM and APM? What is their full name? And how are they functioning?
Please help me, I'm stuck with it and can't find explanation anywhere ?
Thaks. Tami
Tianhe-2 is a cluster, a set of computers (called 'nodes') linked together with a fast interconnect (network), and a distributed storage system. Most nodes are dedicated to computing (the 'compute nodes'), while some others are dedicated to management ('management nodes'.) Dongarra's document also mentions blades as a synonym to nodes. Blades are a kind of node form factor whose working is similar to a docking station for a laptop.
Traditionally, a node is a full computer, with a main circuitry system (the 'board', or 'motherboard') on which the processors and the memory modules are plugged, a network interface, and possibly a local hard disk, and an operating system.
On Tianhe-2, things are a bit different. A single board is made of two distinct parts (modules) plugged together (the CPM and the APU) and that single board hosts two separate nodes. Rather than having two identical boards for two distinct nodes, Tianhe-2 uses one, two-parts-board for two distinct nodes.
One of the boards (the CPM) hosts the CPUs (Intel IvyBridge) and the memory, plus one accelerator (Intel Xeon Phi) and two network connections, while the other (APU) hosts 5 accelerators. Plugged together, they offer two nodes, each with 2 CPUS and 3 accelerators and one network connection.
The Intel Xeon Phi is an extension card, that is plugged to the main board. In that extension card lives a fully-featured mini-computer with a CPU, some memory, and ... a tiny motherboard.
The exact meaning of CPM and APU (also referred to as APM in the Dongarra's document, which looks more like a typo(?) though it was quoted in many many places) is nowhere to be found, one could guess it means Central Processing Module and Accelerated Processing Unit or a variant of it.