One of the major challenges of the opencluster project, part of the CERN openlab framework, is to take maximum advantage of the 10 Gbps technology. A first series of tests has been conducted between two Linux-based Hewlett Packard rx2600 computers equipped each with two 1 GHz Itanium-2 Intel processors. The two computers were directly connected ("back-to-back" connection) through 10 GbE Network Interface Cards (NICs) from Intel (see recent news). The transfer reached a data rate of 755 MB/s, that is, approximately 3/4 of the maximum attainable bit rate of the interfaces.

The transfer took place over a 10 km fiber. It used very big frames (16 KB) over a single stream, and involving the regular suite of Linux Kernel protocols (TCP/IP). When using “jumbo frames” (9 KB), the same test reached 693 MB/s.

The next stages of the test campaign will include continued tuning of the parameters, evaluating next version of processors and inserting Ethernet switching between the end-systems.

The openlabTeam