News

Mainframe Technology Lightens Windows Server’s Load

• By Stuart J. Johnston
• May 25, 2006

It’s aim -- improve main CPU performance and throughput by offloading network packet processing.

"The raw cost performance that we're going to see changing over the next four or five years won't be the rate of the past, it will only be a doubling, or at most a tripling,” Chairman and Chief Software Architect Bill Gates told the audience at his WinHEC kick off keynote on Tuesday morning.

While much of the performance gains Gates cited will come from adding additional cores to CPUs built using smaller and smaller circuitry, performance must be gained anywhere it can be found, including lightening the load on the main CPU. In this case, The Scalable Networking Pack blends a technology borrowed from the mainframe world with Windows Server 2003.

“These are proven concepts from the big iron world,” says Ian Hameroff, senior product manager in Windows Server marketing.

Perhaps more importantly, the same technology will be included in Longhorn Server and Windows Vista, he says.

Microsoft announced Tuesday that the final code for the Scalable Networking Pack is currently available for download. It runs on Windows Server 2003, providing the ability to process networking code on special network interface cards (NIC) that have their own processors.

These so-called TCP Offload Engine-enabled (TOE) networking cards take on the network packet processing load currently handled as part of operating overhead by the server’s main processor. In fact, company officials said this week that TOE NICs running Microsoft’s Scalable Networking Pack can reduce CPU overhead on Windows Server 2003 machines by 20 percent to as much as 100 percent.

“Integrated support for the latest networking offload technologies, such as TCP Offload Engines and Intel I/O Acceleration Technology helps to reduce potential operating system bottlenecks related to network packet processing,” according to company documents. “Scalable Networking Pack can improve the performance and scalability of such data-heavy workloads as file storage, backups, Web servers, and media-streaming,” they continue.

Hameroff adds that the technology will also ship as part of Windows Vista and, ultimately, in Longhorn Server as well. He likes to compare the concept to the common usage today of graphics accelerator cards that have their own dedicated graphics processors onboard. “[With the networking pack] we’re laying the foundations to do the same with network I/O (input/output),” he says.

No changes are needed to applications. And many existing servers running Windows Server 2003 can be updated to runn the networking pack by adding a compatible NIC.

The Scalable Networking Pack had been intended for release much earlier but it was held up by a legal scrap Microsoft had with San Jose, Calif.-based Alacritech over alleged patent infringement. That dispute was settled last summer. Part of the settlement was a three-way, cross-licensing deal among Microsoft, Alacritech and Irvine, Calif.-based networking semiconductor company Broadcom Corp.

Tuesday’s release is the first deliverable of Microsoft’s Scalable Networking Initiative, which seeks to cut operating systems bottlenecks associated with network packet processing and to add support for the new networking hardware without requiring customers to change existing applications or network management practices.

A number of important players in the server marketplace have signed on and either already ship or plan to provide network cards and/or servers that support the technology, including Broadcom, Dell, Fujitsu, Siemens, HP, Intel and NEC.

The Scalable Networking Pack requires Windows Server 2003 Service Pack 1 or later and runs on both 32-bit and 64-bit editions of the operating system. It also requires a compatible NIC -- either one that is TOE-enabled or which supports Receive-side Scaling or NetDMA. The networking pack is available for download here.