InfiniBand and Ethernet are the leading interconnect solutions for connecting servers and storage systems in high-performance computing and in enterprise (virtualized or not) data centers. Recently, the HPC Advisory Council has put together the most comprehensive database for high-performance computing applications to help users understand the performance, productivity, efficiency and scalability differences between InfiniBand and 10 Gigabit Ethernet.
In summary, there are a large number of HPC applications that need the lowest possible latency for best performance or the highest bandwidth (for example Oil&Gas applications as well as weather related applications). There are some HPC applications that are not latency sensitive. For example, gene sequencing and some bioinformatics applications are not sensitive to latency and scale well with TCP-based networks including GigE and 10GigE. For HPC converged networks, putting HPC message passing traffic and storage traffic on a single TCP network may not provide enough data throughput for either. Finally, there is a number of examples that show 10GigE has limited scalability for HPC applications and InfiniBand proves to be a better performance, price/performance, and power solution than 10GigE.