November 15, 2013

Why is Supercomputing Super?

The Tianhe - 2 supercomputer
According to the Oxford Dictionaries, a computer can be defined as "an electronic device which is capable of receiving information (data) in a particular form and of performing a sequence of operations in accordance with a predetermined but variable set of procedural instructions (program) to produce a result in the form of information or signals". All computers follow the basic IPO+S (Input-Process-Output + Storage) model, but the scale can greatly vary. It can range anywhere from a computer powered solely by wine, to the Tianhe-2 supercomputer being assembled in China.

When the average consumer thinks of a computer, they think of brands - namely Acer, Asus, HP, Lenovo, etc. These manufacturers create the final package of the computer, its exterior. But, what happens when you look inside? A computer, like many electronic devices, is comprised of several key, specialized components, all working together in unison to achieve a goal - which is set by developers.

Many of us use computers, often facing the often-occurring, dreaded phenomenon known as "lag". This can happen because of many factors, one of which is slow or outdated components. The "core" components of a computer can be widely debated, so for our purposes, I'll just focus on the CPU, RAM, storage drives, and GPU. When purchasing a new computer, we look for key points like a "3.00 GHz dual-core CPU" or "4 GB of RAM". These specifications will meet the needs of the average consumer, although power users and gamers will look for something with more oomph.

Everyday tasks like using word processing applications, browsing the internet, or checking email doesn't require much processing power - calculating the physics and motion of each object in a flashy AAA game does, however. For this application, we'd look around for something like a quad-core CPU coupled with a discrete GPU from either NVIDIA or AMD. But, what about when we evolve from calculating physics in games to physics of a larger scale, say nuclear detonations? Aside from purely militaristic methods, often supercomputers are used for scientific purposes, running simulations for fields of study including astronomy and climate change.

In order to process these complicated instructions and simulations, equipment on a much larger scale is required - as its processing ability is thousands, if not tens of thousands or hundreds of thousands times faster than your average home PC. Instead of one CPU or case, it comes decked out with thousands of CPUs jammed into racks. Some even come with a GPU-like processor known as a co-processor, meant to make calculations alongside the CPU, but at a much greater speed.

If you thought your home computers took up a lot of room, think again. Supercomputers, like the Tianhe-2, take up area measured in the hundreds of square metres. All that room is used holding blades, cabinets, racks, cooling systems, interconnects - you get my point. Due to its super size, it requires a super price tag, one spanning into the hundreds of millions - dwarfing any consumer grade computer ever built.

Source: Jack Dongarra