Modular Intel® Architecture Platform Helps QLogic* Cut Development Time and Costs
Summary
Vendors in the fast-evolving storage area network (SAN) market segment are under pressure to increase throughput and pack more functionality into less space – even while a declining price curve is putting the squeeze on profits. To offset these pressures, developers need modular components to help save development time and reduce the cost of new network solutions.
Increasingly, vendors are turning to embedded Intel® Architecture building blocks to meet the required performance characteristics. Providing a single platform-based hardware design environment for all appliances, embedded Intel Architecture allows developers to modify their designs in software, resulting in superior flexibility and scalability for more efficient development and faster time-to-market. In addition, vendors can extend product lifecycles because existing hardware platforms can support ongoing software-based upgrades.
In developing the industry’s first 2 Gigabit Fibre Channel Switch in a 1U chassis, QLogic Corporation capitalized on all of the design advantages built into the Intel Architecture platform. This case study shows how an Intel Architecture-based single-board computing module from PFU Systems* (formerly Cell Computing*) enabled QLogic Corporation to trim months from its product development cycle, cut its up-front development costs and mitigate the risk of new product development.
Background
The QLogic SANbox2* switch product family includes a variety of edge switches that provide fabric connections to heterogeneous servers, storage devices, directors and other switches in the storage area network. In the development of the latest-generation SANbox2 Fibre Channel switch, QLogic’s design goal was to double the throughput speed over existing 1 Gigabit switch products and pack this additional performance in a 1U chassis. Specifications called for the switch to provide 2 Gbps full-duplex throughput on all ports, while maintaining 1 Gbps connections to existing storage devices and servers, and automatically supporting 2 Gbps devices when they are added to the network.
The Challenge: Deliver Big Performance in a Small Package
To bring this high-speed, small form switch to market, developers faced several design challenges. Demanding performance requirements meant that QLogic would need a new CPU solution in its SANbox2 Fibre Channel switch. Although switching tasks are handled by specially designed ASICs, a CPU performs the management, control, and interrupt-handling functions. Rapid acceleration of network speeds and the need to support multiple complex point-to-point connections require a management processor with the performance headroom to meet future requirements.
Power consumption, thermal output and reduced real estate provided additional design challenges. The new management processor for the SANbox2 switch would need to provide enhanced performance while at the same time meeting the increasingly restrictive form factor and thermal management constraints of the design. While the existing 16-port 1 Gbps switch was designed in a 2U chassis, the SANbox2 switch would have to fit in a 1U chassis – leaving developers with minimal design room.
QLogic also determined that the new management processor must be compatible with the Linux* OS. While QLogic had written its own OS kernel for its 1 Gbps design, developers wanted to move to the Linux OS to take advantage of its protected kernel and ability to support a robust file system. Linux also offered the advantage of numerous existing applications backed by millions of hours of testing.
To add pressure to the development team, QLogic declared its intent to demonstrate the new 2 Gigabit switch – fully interoperable with legacy devices – at a forthcoming trade show. The accelerated development cycle meant that the new CPU design would need to be debugged and ready by the time the ASIC development was completed.
The Solution: Run with Proven Intel Architecture to Meet Tight Time-to-market Demands
Intel Architecture met all of the demanding requirements for the new switch design. It offered proven support for Linux and the ability to run QLogic’s ported application code. The scalability of Intel Architecture was also an important benefit. By adding multiple ASICs, QLogic could build higher-capacity switches. At the same time, the embedded Intel Architecture low-power processor roadmap would enable the future implementation of enhanced processing performance to meet the needs of SAN applications including controlling name-servers, maintaining state machines, and loading files from RAM.
QLogic engineers were also impressed with the robust context-switching capability of Intel processors, which enables the management of multiple devices and device types on the network. The remaining decision for QLogic was to choose the right implementation strategy to meet its time-to-market objectives.
Modular Approach
QLogic faced the choice of creating a custom design by integrating individual components on a system board, or opting for a modular solution. To streamline the design process, QLogic chose an ultra low-power "System-on-a-Module" single-board computer solution from PFU Systems (formerly Cell Computing). Based on an embedded Intel processor, the PFU Systems module has a typical power dissipation of just 3.2 W.
Using the pre-validated compute module meant that QLogic could buy an off-the-shelf solution, plug it into the system board, and focus on development of its next-generation Fibre Channel switch ASIC, a strategy which QLogic credits with substantially mitigating the risk associated with a custom hardware design. The modular design approach enabled QLogic to move forward with the job of creating a prototype by taking the ASIC from its existing 1 Gbps Fibre Channel switch device, writing drivers and attaching it to the system board via a PCI connector.
As a result, QLogic was able to demonstrate a fully functional 2 Gbps Fibre Channel switch – communicating with legacy devices – in the Fibre Channel Industry Association booth at COMDEX. The successful Fibre Channel switch development effort created a model for QLogic’s future development programs, including InfiniBand* solutions.
"Since our time-to-market concerns were so high, we decided not to chance using a lesser-known entity. From a risk-tolerance standpoint, Intel’s Architecture was a no-brainer. In the case of the SANbox2 switch, the overall design took about 8 months.
"We chose Intel Architecture because it is the most widely adopted, well-proven and cost-effective architecture available. It gives us lots of options. The rich tools environment of Intel Architecture eases the development of robust name servers and arbitrated loop state machines that require a high level of interaction with the processor.
"Using the Intel Architecture-based compute module meant that in prototyping we could run our own applications on the Intel processor before our ASIC was available. When we got our ASIC, we were ready. The ability to debug the application on the main board without waiting for the ASIC meant that we were passing data in three days after dropping it in. Without the embedded Intel Architecture reference design we could never have gotten there."
Michael Walton, Director of Product Marketing QLogic Corporation Server Products Group
The Future: Cost Pressures
The networked storage market segment has become extremely cost-sensitive, driven in part by the rapidly declining price curve for storage devices. Because Intel offers a long-term product roadmap, and proven, standards-based architecture QLogic is able to keep development costs down.
As a leading developer of networked and embedded SAN solutions, low power, cooling and limited real estate present a continual challenge for QLogic as it packs more storage switching and control functionality into less space. The use of Intel Architecture building blocks, coupled with the modular solutions from PFU Systems, helped QLogic meet its goal of being first to market with what the company terms "enterprise-level SAN performance at mainstream price points."
QLogic*
