networkZONE Products for the week of January 29, 2007

SolarFlare Communications Says…
Industry's Lowest-Power 10 Gigabit Ethernet Controller
Standards-compliant 10GBASE-T server adapter reference design will accelerate growth of 10 Gigabit Ethernet market

Solarflare Communications has announced Solarstorm, the industry's lowest-power 10 Gigabit Ethernet controller, along with the sampling of this silicon. The Solarstorm controller operates at just 2.2 watts, setting the bar for low power. In addition, the company introduced the industry's first standards-compliant 10GBASE-T server adapter reference design, along with 10GBASE-CX4 and XFP optical server adapter reference designs. Because these reference designs hit the sweet spot of low power, high performance, standards compliance, and simplicity, they will accelerate the adoption of 10 Gigabit Ethernet.

The new Solarstorm controller delivers the optimal balance of performance, power, and price, enabling the widespread implementation of 10 Gigabit Ethernet in data center and enterprise networks. "The combination of Solarflare's new Solarstorm 10 Gigabit Ethernet Controller and 10Xpress 10GBASE-T PHY will enable our OEM customers to bring to market 10 Gigabit Ethernet server adapters at about the same cost as quad-port 1 Gigabit Ethernet server adapters. Such cost effectiveness will accelerate deployment of 10 Gigabit Ethernet," said Bruce Tolley, vice president of marketing at Solarflare.

Solarflare's Solarstorm controller uniquely possesses several key features that meet OEM demands:

"I am very impressed by the low power dissipation of the Solarstorm 10GbE controller" commented Bob Wheeler, Senior Analyst, The Linley Group. "This is key for enabling the current generation of 10GBASE-T PHYs to drive the full 100 meter distance, while staying well within the constraints of the 25 watt PCI Express limit."

Solarstorm is capable of leveraging Intel's QuickData Technology platform announced on October 16, 2006, at the Intel Developer's Forum in Taipei.

"Intel's QuickData Technology complements Solarflare's new high-performance 10 Gigabit Ethernet controller by minimizing the system overhead associated with data movement to and from the network." Jim Pappas, Director, DEG Technology Initiatives and Industry Marketing (TiiM) of Intel remarked: "Finding the right division of labor between the 10 Gigabit Ethernet controller and the motherboard chipset is key in designing a solution that will scale with time. A combination of enhancing the motherboard chipset with features like Intel's QuickData Technology and putting the right stateless offload features into the 10 Gigabit Ethernet controller provides a solution which preserves the network infrastructure, and removes the burden of deploying new protocols."

By enabling products from other companies to use the acceleration engine present in Intel Xeon 5100 series-based servers, Intel QuickData Technology helps the industry benefit from the increased speed, scalability, and server reliability that only Intel enterprise platforms can provide.

10GBASE-T and Server Adapter Reference Designs
The IEEE 802.3an Standard for 10GBASE-T requires that all PHYs for 10Gigabit Ethernet on twisted-pair copper reach 100 meters. Furthermore, the TIA-568B and the TIA-962 cabling standards also require support for 100 meter channels of copper cabling. Solarflare is the only company sampling a standards-compliant 10GBASE-T PHY with greater than 100 meter reach. The Solarstorm 10GBASE-T server adapter reference design supports distances of greater than 100 meters on UTP Category 6A cabling, 100 meters on STP Category 6, 55 meters on UTP Category 6, and 45 meters on UTP Category 5E cabling. This reference design uses Solarflare's currently sampling 10Xpress PHY which has been tested privately and publicly by multiple third parties to greater than 100 meter reach even in the worst-case, four-connector topology with a 6 around 1 alien near end cross talk (ANEXT) environment.

Solarflare is the only company sampling a 100-meter, standards compliant 10GBASE-T PHY. The IEEE 802.3an standard requires that all PHYs claiming compliance support 100 meter reach on Category 6A cabling. "Anixter recommends Category 6A cabling infrastructure for data center applications, and is the only distributor that independently tests 6A cabling in the industry," stated Andy Jimenez, Vice President of Technology at Anixter, a distributor of communications products. "Additionally, both the international and US standards (ISO 11801 and TIA/EIA 568-B) and the data center standard (TIA/EIA 942) require 100 meter reach utilizing four connector cabling topologies," Jimenez commented.

In addition to the 10GBASE-T server adapter reference design, Solarflare is offering 10GBASE-CX4 and optical (XFP) server adapter reference designs. All of the reference designs include schematics, bill of materials, layout files, critical components lists, and errata. All three reference designs are available in a low profile PCI Express form factor.

Solarflare is publicly demonstrating the SFE4001 10GBASE-T server adapter reference design, which operates at 16 watts while compliant with the 10GBASE-T standard's specified reach of 100 meters.

analogZONE Says . . .

From the looks of the SolarFlare SFC4000 Solarstorm 10GbE MAC/controller and adapter card reference designs, it seems they figure the best way to accelerate the market for their 10G PHY products (such as their pre-standards Cat5e copper transceiver (reviewed here March 2004) is to roll out end-to-end solutions that make the leap to 10GbE as easy and straightforward as possible for blade manufacturers and the handful of server manufacturers who decide to roll their own 10G cards. While their new MAC/controller looks to be technically up to snuff, much of its eventual success will rest on several critical assumptions about the evolution of the systems they'll be going into that shaped its basic architecture. As we'll see, SolarFlare's most notable assumption is that the increased performance and TCP-friendliness of the next generation of CPUs and operating systems will allow them to deal with 10G data rates without resorting to silicon-intensive offload engines or modifications to the TCP/IP stack used by many early 10G products.

The Solarstorm controller includes the basic MAC logic required for a 10GbE connection plus several basic hardware functions that support what SolarFlare calls stateless offload. In this arrangement the hardware that performs wire-speed checksums for IDP, UDP and TCP transactions is completely transparent to both the upper-layer hardware and the TCI/IP stack. It even performs a header and data digest (a CRC operation) function which is often disabled to speed throughput because it is so compute-intensive.

The controller also accelerates I/O virtualization by providing a bypass stage that handles hypervisor forwarding operations between the host system and its virtual guest operations. Its on-chip hash table does not divert all flows passing through the device for offload, but is structured to identify deal with the most frequently-occurring operations for offload. This allows it to resolve and accelerate enough of them to greatly relieve host processor. It supports 4096 virtual systems via an on-chip lookup table and VNIC interface logic.

A transmit pacing mechanism keeps each VNIC separate from the others and ensures they maintain bandwidth allocations. Priority is assigned to provide an upper boundary on the number of packets/s each VNIC can pass and guarantees that packets are transmitted in the proper order. QoS and bandwidth allocation to each virtual system is handled by a multi-level scheduler which uses a weighted round-robin algorithm. Each of its queues can have one of 20 priority levels.

The Solarstorm VNIC virtualization hardware can enable a connection to a guest OS through either a traditional virtualization OS (or machine monitor) or directly through a hardware interface that handles MAC address mapping and traffic scheduling. Bypassing the virtualization OS saves lots of processor power which would otherwise be burned in the virtualization layer (see Fig. 1). Liberating the host from supporting this middle layer frees up enough MIPs that it goes a long way towards justifying the elimination of the heavy-duty TCP offload hardware most early 10G controllers used. SlarFlare also contends that modern processor chip sets have much more DMA throughput and processing power that greatly improves their ability to terminate TCP/IP. This, and the TCP-friendly capabilities in the newer operating systems (such as receive-side scaling) shrinks the advantage TOE engines can provide.

SolarFlare asserts that, given these trends, today's offload technologies will be completely unnecessary after the next generation or two of processors deliver up the speed to handle 10G traffic without assist. They also say that the current offload features require software mods and other kludges that most applications do not use anyway.

If their assumptions about the decreasing importance of heavy-duty offload are correct, SolarFlare's Solarstorm MAC/controller should be well-positioned to address the early wave of demand for low-cost 10G connections in blade, server, storage, and cluster interconnect systems. The simpler lighter-weight controller uses lots fewer gates which results in a 2.2 W operating power (vs. Chelsio 15+ W). It's too bad that their two-package PHY is not as power-frugal (it draws around 12 W)but I guess that's to be expected for a first-generation 10G product. I can't wait to see what the next year holds as SolarFlare rolls out its next-gen PHY and companies like Aquantia uncloak and deliver their own 10GbE PHYs but, until they arrive, Solarstorm's lower power consumption means the early adapter cards won't be complete thermal nightmares.

About the only other issue I'd take with SolarFlare is that the Solarstorm only supports a single 10G connection. This is not an immediate problem since the high power consumption of the early PHYs makes a two-port card impractical but this should change rapidly as PHY power drops below 10 W. Since an eight-lane PCIe interface typically found on an adapter card can support roughly 20 Gbit/s worth of throughput, the baseline for 10GbE NICs will be two ports. This would necessitate a second controller chip on the card or, more likely, a new two-port controller somewhere in SolarFlare's immediate future.

The SFC4000 Solarstorm 10 GbE MAC/Controller is available now. SolarFlare was reluctant to discuss a specific price for the part but they were willing to say that they were shooting for a total BOM cost for a 10GBASE-T adapter card that would allow it to sell for $400 - $600, or roughly the price of a Quad GbE server NIC.

SolarFlare has also released three PCIe reference designs for adapter cards which support 10GBAST-T, XFP optical and 10GBASE CX-4 interfaces (see Fig. 2). The designs include drivers for Linux 2.4/2.6 and Solaris. SolarFlare has also provided drivers for Windows 2003 and Vista.

Evaluation boards based on the reference designs ($1500 for complete reference kit) are also now available. The 10GBASE-T version draws around 16 W (9 W less than 25 W maximum for PCIe cards), the CX-4 variant draws 5.4 W, and the optical version consumes around 7.5 W.

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