Characterization of an Application for Hybrid Multi/Many-core Systems


In my last blog post, I illustrated a paradigm shift in chip technology and how node architecture must significantly change to support these trends. In this post, I will discuss a way to characterize applications for investigating approaches to moving forward into the world of multi- and many-core hybrid systems. When porting/optimizing an application to the new generation of hybrid multi-/many-core systems, one must identify enough parallelization to utilize two levels of parallelism on the node. Whether the node is an accelerated node or a many-core node, a significant amount of threading on the node is a requirement for good performance. The days of using messaging across all the cores on a node are over. Additionally, the lower-level ... [ Read More ]

What Sank the First Successful Wartime Sub?


The story of the first wartime “kill” by a submarine — the H.L. Hunley, built to help defend the Confederacy in the U.S. Civil War — is a thrilling tale of naval bravery. It is Feb. 17, 1864.  The Hunley, engaged in a desperate bid to break through the Union’s blockade of Charleston Harbor, attacks and sinks the Union’s USS Housatonic. But shortly afterward the Hunley herself sinks for reasons that are never understood, creating one of naval history’s great mysteries. Just sailing the Hunley required bravery. The vessel was built from a 40-foot-long cylindrical iron boiler, tapered at both ends to provide a measure of streamlining. There was no engine: The 1,240-ton sub was powered by seven sailors, turning a hand crank that drove the ... [ Read More ]

We put the bugs in … we take the bugs out!


Many years ago I was leading a workshop on programming methods, and I can’t remember which language we were using at the time — it doesn’t matter — but we were covering numerous high level software development flows like spiral, V-model and waterfall. An astute engineer in the middle of the room raised his hand and interrupted the slide show discussion. “This is all nice, but at my company,” he said, “we have a simpler two-step process. We put the bugs in, and then we have to find them and take them back out!” The room erupted in laughter and nodding heads. It was a powerful and insightful summary, eloquently and humbly stated. It didn’t really matter what the programming method, model or language were; coders all need a method of ... [ Read More ]

“Titan” Supercomputer: More than an Engineering Marvel


Like Cray, the Oak Ridge Leadership Computing Facility (OLCF) at Oak Ridge National Laboratory (ORNL) is dedicated to solving the world’s toughest problems using supercomputers. Perhaps that’s why Cray and ORNL have a relationship dating back three decades to when the facility’s first Cray system, a Cray® X-MP™, came to East Tennessee in 1985. After four years of administering Cray systems for the U.S. Air Force in the early ‘80s, I came to Oak Ridge to help run the X-MP system. Since then, I’ve seen a long line of Cray supercomputers cycle through ORNL. Each new generation of systems has improved upon its predecessors in small — and oftentimes big — ways that helped advance ORNL’s broad science and energy mission. The most recent ... [ Read More ]

The Cray Shasta System


You may have seen Cray’s recent announcement regarding our next generation supercomputer (codenamed “Shasta”) that we anticipate delivering to the Department of Energy's Argonne National Laboratory (ANL) in the future. We don't normally talk about a new system architecture this far in advance, but since it's come out in the announcement, I thought I'd provide a brief overview of the Shasta system. Shasta will be the successor to both our Cray® XC™ line of supercomputers (previously code-named “Cascade”) and our Cray® CS™ line of standards-based cluster systems. As such, Shasta is the most flexible system we've ever designed and the full embodiment of our adaptive supercomputing vision. We've been out talking with customers from HPC ... [ Read More ]