June 2, 2008 -- 10-Gbit/sec rack-to-rack copper interconnects of up to 30 meters (approximately 100 feet) have been demonstrated by UK chip-maker Phyworks, using technology the company originally developed for the optical module market.
The equalization and clock and data recovery (CDR) capabilities of Phyworks' PHY2060 IC have been successfully applied to active serial copper cable assemblies, which are currently being used by cable and connector OEMs on a trial basis, reports the company. The complete 10G assembly achieves error free transmission at a latency of just 120 ns over 30 m of 24 AWG twin-ax copper cable.
"More than 80% of high speed data center interconnects are under 30 m, and existing optical and copper solutions are just too expensive, bulky, and power-hungry for the task," contends Phyworks' CEO Stephen King. "We have proved that the equalization and CDR technology developed to achieve high performance in the optical market can also guarantee the performance of shorter range copper communication links, which takes cost, weight and power out of the data center."
The company maintains that, under pressure to support a far wider range of voice, video and data services while keeping capital expenditures down, data center operators are looking for new ways to connect systems that are low in cost and power, yet which ensure minimum latency and maximum possible quality of service. Able to be integrated into incumbent XFP and emerging SFP+ ports, Phyworks says its PHY2060 IC enables new copper cable interconnects to be hot-plugged into existing optical ports, providing data center operators with greater flexibility.
Also, the company notes that 10G inter-rack connections up to 30 meters have traditionally depended on 10GBASE-SR optical modules and 10GBASE-CX4 copper cable. In the XFP connector format, a pair of 10GBASE-SR optical modules can cost up to $400 - $600, while a substitute active serial copper cable assembly is predicted to cost approximately $150 - $200.
40% smaller in cross-section and 30% lighter, Phyworks maintains that twin-ax copper cable is far less bulky than CX4, and at $1 per meter compared to CX4's $7 per meter, significantly more cost-effective. In addition, contends the company, CX4's need for line-card mounted quad re-timers and quad pre-emphasis drivers, and the PCB space to support 8 data lanes, also adds considerable overhead.