Cool Threads

A couple of columns ago we touched on the practical rebirth of parallel computing. In case you missed that column (it's in this week's links), the short version is that Moore's Law is letting us down a bit when it comes to the traditional way of increasing the power of microprocessors, which is by raising clock speeds. We've hiked them to the point where processors are so small and running so hot that they are in danger of literally melting. Forget about higher clock speeds then; instead we'll just pack two or four or 1000 processor cores into the same can, running them in parallel at slower speeds. Instantly we can jump back onto the Moore's Law performance curve, except our software generally doesn't take advantage of this because most programs were written for single cores. So we looked back at the lessons of parallel supercomputers, circa 1985, and how some of today's software applies those lessons, such as avoiding dependencies and race conditions.

But we didn't really talk