networkZONE Products for the week of April 14, 2008
Solarflare Communications Says…
First Single-Chip 65-nm 10GBASE-T Transceiver
10GBASE-T PHY and enhanced controller drive widespread adoption of 10 Gigabit Ethernet
Solarflare Communications has announced its next-generation 10GBASE-T PHY and enhanced 10GbE controller products. The new 10Xpress 9001 PHY runs at under 6.0 watts and the Solarstorm 4000E virtual network interface card (vNIC) controller performs at less than 2.2 watts. When combined on a server adapter, Solarflare’s 10GbE silicon PHY and controller deliver 10 times the performance of a 1 Gigabit NIC at half the power consumption of previous 10GbE server adapters.
The 10GBASE-T PHY supports high-density 10GbE switches and dual port 10GBASE-T adapter cards. The PHY also supports legacy infrastructure and includes cable diagnostics to help ease deployment. The company’s controller is the best performance-per-watt over standard copper Ethernet cabling and reduces power consumption by 50 percent. The innovative architecture and advanced features of Solarflare’s next-generation silicon products provide switch and server vendors with cost-effective technology to build dual-port 10 Gigabit server and storage adapters, and high-density 10GbE switches. This allows companies to easily deploy advanced applications over their networks.
“As business demands continue to grow, there is an ever-increasing need to deploy advanced applications, such as iSCSI and virtualization, that require the next level of networking,” said Jag Bolaria, senior analyst at The Linley Group. “Solarflare is showing its leadership through this PHY and controller silicon, both required to build standards-based 10GBASE-T products that can be deployed over copper wiring. By addressing the power, performance and cost of 10 Gigabit networking, Solarflare’s next-generation silicon enables 10GbE for volume deployment.”
Solarflare designs and develops the highest performing, lowest power 10GbE controllers and 10GBASE-T transceivers on the market. The company’s next-generation PHY and controller are optimized for applications such as virtualization, network storage convergence and rich media data. They enable switch and server original equipment manufacturers (OEMs) to cost effectively build standards-based products for enterprises and data centers.
“Solarflare continues to lead the market with the highest performing, lowest power, IEEE standards-based 10 Gigabit Ethernet silicon,” said Russell Stern, CEO of Solarflare. “Our next-generation technology is a first in our industry as we have the only solutions that address both power and performance issues. We’re providing enterprise-class products to OEMs that will continue to push forward the adoption of 10 Gigabit networking.”
Specific features of the 10Xpress 9001 PHY include:
- Lowest power, smallest package 10GBASE-T PHY
- Enables high-density 10GbE switches up to 32 to 48 ports in one rack unit (RU) form factor
- Enables dual-port 10GBASE-T server adapters that are compliant with the PCIe power specification;
- Several low power modes (from 100s of mW to sub 6.0 W) enable efficient power management
- Multi-speed auto negotiation down to 100Mbits/s
- Support for legacy Ethernet and legacy infrastructure (100Mbits/s, 1000Mbits/s, Category 5, Category 5E, Category 6 UTP and STP copper cabling)
- Provides investment protection and enables an asynchronous upgrade cycle for independent server and switch upgrades
- 10GBASE-T cable diagnostics to address line breaks and reduce network downtime
Specific features of the Solarstorm 4000E vNIC controller include:
- Highest performance-per-watt controller in the industry
- 2.2 watts, 18 Gbits/s bidirectional throughput with 1500 Byte maximum transport units (MTUs)
- Enables single-port, sub 10 Watt adapters
- Virtualization and iSCSI protocol acceleration with line-rate performance
- vNIC architecture supports up to 4096 virtual machines per interface
- Virtualization acceleration with line rate performance for all leading platforms, including Xen/Citrix, VMware and soon Microsoft
- iSCSI data digest offload for SAN/LAN convergence
- Scalable architecture for upcoming octal core CPUs and platforms provides for flexible, future-proof technology
Solarflare 10Xpress 9001 PHY is one of a small handful of products in the home stretch of the race to deliver commercially-viable 10GbE copper technology to bandwidth-hungry networks. The new device seems to reap the power savings and performance benefits that an experienced design team can wring out of integrating a previous three-chip set and migrating it to a more aggressive process node. Since my briefing did not include many deep technical details about the transceiver’s innards, I have a few lingering questions about whether the 9001 real-world performance will completely match its claims that will only be answered after I attend a few trade shows and talk to some folks actually running the silicon. Despite any misgivings, my previous experience with Solarflare leads me to believe that they have a credible offering that should be able to achieve the company’s stated goal of enabling manufacturers to offer a single-port, sub-10 W, 10Gbase-T NIC with a street price of $400 - $500 this year.
The 9001 10GbE single-chip PHY integrates the transceiver, its companion AFE, and the SiGe low-noise PGA that form their current three-chip SFX7101 (a design that’s closely-based on their pre-standards chip set that I reviewed here back in March 2004). Its companion SFC4000E controller more closely resembles their SFC4000 controller reviewed here January 2007, but boasts more throughput plus improved receive side scaling (RSS) support and virtualization acceleration.
According to Solarflare, creating a single-chip 10G PHY was made possible by the migration from the 90-nm process used by the earlier chip set to a 65-nm process. Besides allowing them to crowd more stuff on to a single chip, the higher fT of the smaller transistors gave them the speed needed to move the front-end PGA from a SiGe process to bulk CMOS and to use a digital implementation of several functions that had previously been analog.
Moving to 65 nm gave Solarflare about half the power savings that the design eventually realized. Around half of the remaining savings are a result of eliminating the power-hungry inter-chip interfaces, but the designers had to get really aggressive about hundreds, if not thousands, of small details to squeeze out the final design flow improvements that drove the transceiver maximum power consumption below 6 W (Solarflare assures me that the power consumption figures they shared were for worst-case, maximum-length cable operation under worst-case process corners, temperature, and power supply variation). The new design is laid out with functional blocks that consume around 50 mW, allowing designers to carefully tweak the design at a very low level. This, and aggressive use of clock gating to turn off anything not being used for a particular mode seem to have enabled a 10G PHY that runs cool enough to make higher-density applications possible.
Those high-density applications (mostly high-port count servers and switches) will also benefit from the 9001 improved front-end design that simplifies the external hybrid circuitry normally employed to tie its transmit and receive pairs together. According to Solarflare, they have developed and proven a patent-pending hybrid design that uses only inexpensive passive components and requires less power to drive than conventional circuits. This design is licensed with the sale of Solarflare’s transceiver silicon and is included in reference designs for implementation on the customer’s circuit boards. It will be interesting to see how this approach compares to another single-chip 10G PHY which is scheduled to uncloak in the next few weeks that claims to have eliminated the need for any kind of external hybrid.
Another important feature added to the 9001 is its auto-negotiation capability that allows it to sense and link up with any Fast Ethernet or Gigabit Ethernet connection. The ability to fall back to legacy data rates proved to be a critical part of Fast Ethernet’s rapid market adoption back in the early 1990s, and what has made it possible for computer makers to deliver computers with GbE connections on their motherboards well before Gigabit switches were the norm in homes and offices.
Both the 10Xpress 9001 PHY and its companion SFC4000E controller offer significant performance improvements over their previous incarnations that have allowed the chip set to demonstrate 9 Gbit/s line rates (and bi-directional throughputs as high as 18 Gbit/s) while supporting XEN and VMWare in benchmark testing. Of course benchmarks don’t always reflect what a chip will encounter in the real world so I asked Solarflare for a few details about their test set-up.
From the information I received, it looks like the benchmarks were carried out on a Supermicro 6025W-NTR+B rack server equipped with two Intel Penryn 3.2 GHz processors and a pair of Solarflare SFE4003 B0 reference design boards driving a CX4 connection in a back-to-back configuration. The server was running a Chariot HighPerf benchmark program with the Performance Measurement Settings enabled. Under these conditions running 1.5 kbyte MTU packets, they were able to demonstrate an 18 Gbit/s bidirectional line rate at 29% CPU utilization.
The Solarflare decision to run its benchmark using only maximum-length packets aroused my interest, since I’ve seen several instances where an abundance of shorter-length packets can affect the throughput of packet processors, inspection engines and other silicon that looks closely at packet headers. I wondered if this might affect the performance of the 4000E controller and asked the company if they had any performance data for a stream of minimum-length packets or some mix of short and long packets. Unfortunately, I have gotten no reply from Solarflare at the time this story was filed, although I suspect that this silence is more likely a function of a very busy schedule as the company rolls out its new products than an attempt to suppress potentially unflattering information. On the other hand, I have no explanation for why the benchmark was run over CX4 cabling rather than the more commonly-used Cat-7 and Cat-6a Ethernet cabling.
Despite these unanswered questions and the sparse information I was given about the transceiver’s internals, I am fairly certain that it will deliver performance that’s relatively close to the specs in their release. The fact that they have demonstrated the chipset ability to run over 50 m of plain vanilla Cat-6 cabling and 15 m of CX4 indicates that its equalization and echo cancellation are at least up to an acceptable level. I do have some minor concerns about whether the integration of the AFE and PGA may have cost them a bit of front-end linearity, sensitivity or noise immunity that could limit performance under challenging channel conditions but have no specific observations to back this up.
Another common problem with designs like this is that they involve a significant amount of mixed-signal elements that they can be overly-sensitive to process variations that cause experience unexpected yield problems. Since Solarflare did share with me some of their efforts to take advantage of the 65-nm process faster device speeds to move as much of their design to the digital realm as possible, I think they may have ducked at least some of the potential hazards here.
If Solarflare is able to deliver on its promises it will be a good candidate to help deploy the lower-cost copper-based 10G connections that the market seems to be holding its breath for. Market acceptance should also be strengthened by the chipset ability to efficiently support most common virtualization schemes. Meanwhile its lower operating power makes it easy to design a 2-port 10GbE NIC that draws around 18 W, allowing manufacturers to easily meet the 25 W/slot limit imposed by the PCIe spec.
The 10Xpress 9001 will sample in May 2008 to top-tier switch and server OEMs and the Solarstorm 4000E vNIC is sampling now to tier 1 server OEMs and other select customers. Sample pricing for the 10XpresPHY 9001 is under $100, with substantial volume discounts. Sample pricing for the Solarstorm 4000E vNIC is also listed at under $100 but Solarstorm says it expects that its volume pricing will be significantly less than its PHY device.