Archives for August 2006

How do we improve locality of reference?

Parallel execution is the most common technique for speeding up large applications, but it alone is not sufficient for all cases. In particular, Amdahl’s Law states that the inherently sequential portion of a program is the limiting factor of speed improvements. An additional tool for performance enhancement is to reduce the effective latency for fetching […]

Is RDMA really that bad?

The paper “A Critique of RDMA” presents a good argument against remote direct memory access in high-performance networks. An overview of the technology is present in an earlier post on the Virtual Interface Architecture (VIA). The VIA model requires an enormous amount of overhead for the initial communication because the software layer must pin the […]

What are some open-source tools for technical computing?

Because of MATLAB‘s sheer popularity, most open source tools mimic MathWorks’s proprietary language. Octave, which started as a teaching tool in a similar vein as MATLAB, is probably the most widely used. Its language is very compatible with MATLAB and the command-line front end can be customized to mimic MATLAB’s editing window. Likewise, Scilab is […]

What is Cray Hood?

“Hood” is Cray’s next-generation supercomputer, and is based on the XT3 architecture. It uses Opterons and an improved SeaStar network (torus topology). Details are pretty light at the moment, but it will be installed next year.

What is OpenFabrics?

OpenFabrics is the new name for OpenIB. The title change reflects the shift in supporting only InfiniBand to supporting both InfiniBand and iWARP. The organization has an “enterprise distribution” of a software stack for these networks. If nothing else, this will give iWARP a leg-up in its competition against Myri-10G.

Why did Microsoft release C#?

It may be tempting to write off the .NET strategy as merely a ploy to increase dependency on Microsoft’s platform, and indeed that may be a correct assessment. Given that Microsoft holds such dominance on the maturing desktop market, the folks in Redmond must be aiming to expand in the lucrative server sector. It appears […]