How to build your own Watson Jeopardy! supermachine • The Register

Still wowed by Watson's hardware:

Why not build your own Watson-style QA machine?

As it turns out, the basic foundations are there for the taking.

Let's start with the iron – it really isn't that much hardware, after all. With the beta version of the Watson software, IBM started out with a few racks of its BlueGene/P parallel supercomputers, a grandson of the Deep Blue RS/6000 SP PowerParallel machine that played a chess tournament against Gary Kasparov – and beat him – back in 1997. But because the Watson effort was not just a technical challenge, but also a killer marketing campaign for the current Power7-based Power Systems lineup, Big Blue eventually switched the Watson DeepQA software stack to a cluster of Power 750 midrange servers.

To have enough memory and bandwidth to store all the necessary data, IBM put 90 of these Power 750 servers into ten server racks. Each server is configured with four of IBM's eight-core Power7 chips running at 3.55GHz. That gives Watson 2,880 cores and 11,520 threads on which to run its software stack. If the DeepQA software is thread-heavy – and there's every reason to believe it is – you'll need iron with lots of threads.

The 90 servers underpinning the Watson machine had a combined 16TB of main memory, but it looks like that was not evenly distributed across the nodes. The math works out to 182GB per machine, which is a silly, non-base-2 number.