Parallel Extensions to .NET Previewed

The Parallel Extensions to the .NET Framework 3.5, available in a preview version, aim to exploit the parallelism provided by CPUs with multiple processor cores. The Parallel Extensions are particularly important because they use the .NET Framework and are the starting point for a broader Microsoft initiative that is likely to include changes to Microsoft’s programming languages and tools, as well as to Windows itself.

The Need for Parallelism

Moore’s Law observes that the number of transistors that can be inexpensively placed on an integrated circuit doubles every 18 to 24 months. Moore’s Law held reliably as microprocessors were pushed to ever-increasing clock speeds, and each new generation of microprocessor ran existing applications faster than the previous generation.

Although transistor density continues to rise steadily per Moore’s Law, processor speed itself hit a wall in 2003—difficulties in cooling processors running faster than about 4 gigahertz made them impractical in standard PCs. Intel and AMD began to take a different approach to exploiting Moore’s Law: they began to build processors that combine two or more microprocessor cores into a single package. As of Dec. 2007, mainstream CPUs from Intel and AMD contain two cores, four-core CPUs are common on servers, and eight-core versions are on tap for 2008.