Chelsio announces TOE for Microsoft Chimney architecture



Chelsio’s T3 Unified Wire Adapters Drive 10GbE Connectivity Into Volume WindowsВ® Servers 

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Sunnyvale, CA, April 7, 2008
– Chelsio Communications Inc., the industry leading provider of 10-Gigabit Ethernet unified wire solutions, today announced availability of its TCP/IP offload engine (TOE) technology fully supporting the Microsoft® TCP Chimney architecture.  Microsoft TCP Chimney allows Windows® operating systems to offload network TCP processing from the CPU to the network controller.  Chelsio is licensing Alacritech Inc. patents to enable Chimney driver support.

TCP/IP processing consumes a high amount of server CPU cycles and at 10Gbps rates, it places a tremendous load on the memory subsystem and the need to offload this burden from the server becomes critical.  TCP Chimney-enabled Chelsio adapters not only free the host CPU from network processing, but also, by eliminating data copy, free up memory bandwidth for processing of applications, thus improving overall application performance and server efficiency.

Performance testing results show that Chelsio’s 10GbE TOE, running with Microsoft’s TCP Chimney stack, doubles network throughput and improves CPU utilization by up to eight times as compared to the same server running without a TOE. In fact, the utility cost savings enabled by TCP Chimney over the data center server refresh cycle are easily a multiple of the cost of the server itself:  TCP Chimney allows more compute power for the investment for the data center managers.  Further, Chelsio’s hardware offload engine also accelerates TCP/IP processing times, yielding better response times and no latency variations for networked applications – critical to the performance of interactive applications.

This major milestone is the result of our long-term collaboration with Microsoft and supports our overall vision for a unified data center fabric, said Kianoosh Naghshineh, president and CEO of Chelsio Communications. Available today, our 10GbE Chimney protocol offload engine opens the way for broad adoption throughout the network, and has set a new standard for TCP/IP offload engine technology.  Our T3 10GbE solution addresses the performance acceleration requirements of CIFS, iSCSI and general networking applications.  The results are clear: using Chimney results in higher bandwidth, lower CPU utilizations, lower server power consumption, and lower latencies.

The outstanding performance, robustness, and scalability of the TCP Chimney architecture are major successes for Microsoft.  We are very pleased to see the availability of the Chimney-compliant 10 Gigabit Ethernet solution from Chelsio, said Mike Schutz, director of product management for Windows Server at Microsoft. Microsoft is pleased to be working with partners like Chelsio to enable broad-based deployment of 10GbE TCP Chimney offload within Windows data centers.

Chelsio Chimney TOE adapters are shipping today. Pricing is $1795 for the S310e-SR-C and $895 for the S302e-C adapter.

About Chelsio Communications
Chelsio Communications is leading the convergence of networking, storage and clustering interconnects with its robust, high-performance and proven unified wire technology.  Featuring a highly scalable and programmable architecture, Chelsio is shipping 10-Gigabit Ethernet and multi-port Gigabit Ethernet adapter cards, delivering the low latency and superior throughput required for high-performance computing applications.  For more information, visit the company online at


Media Contact:
Tim Helms
Helms Communications