RTC Magazine

Blade servers have gained ground over the past few years as an efficient, condensed computing solution in large data center implementations. They are widely used as replacements for pizza box servers and large rackmounts (Figure 1).

The advantages inherent in blade server technology include smaller form-factors, denser computing, expandability, hot-swap capabilities, flexible and fail-safe architecture, reduced downtime, increased redundancy, simplified server management, easier hardware and software integration, and lower heat dissipation and power requirements. These improvements over traditional data center servers provide for a massive increase in deployable resource density and an overall reduction in long-term costs.

Each blade in a chassis is typically a self-contained server. Data center consolidation, advanced communications and remote management of servers required to run 24/7 are just a few of the reasons for large-scale deployments. These deployments are becoming more popular for telecom, telephone and cellular carriers, insurance companies, tax preparers, state and local government agencies and educational institutions, among others.

Although blade servers have a long way to go before they are the standard deployed technology throughout the data center, they are beginning to appear in less traditional implementations such as high-performance computing (HPC).

Newer Blade Technology Enables High-Performance Functionality

Many of the characteristics that enable the use of blades in HPC applications have emerged in recently introduced blade servers. As they become increasingly smaller and more powerful, blades are incorporating technology such as open standard architectures, multicore processors, PCI expansion for multiple I/O functionality, the ability to house multiple OSs, low-power processors and innovative cooling techniques, standard AC electrical connectivity, daisy-chaining and Gigabit Ethernet ports. When these are combined with the growing trend of virtualization, blade functionality increases even more.

The great advantage of an open architecture is that anyone can design add-on products for it. An open architecture also increases the potential for partnerships that enable the integration of design cycle management tools. By integrating the tools engineers already use within the same user interface, open design environments enable greater productivity. Innovative products, open standards and interoperability are fundamental to the mainstream adoption of new services in the HPC world.

The emergence of multicore processors gives blade manufacturers even denser computing options. Chips such as Advanced Micro Devices’ dual-core Opteron processor offer significantly greater computing performance than equivalent single-core devices, yet produce no additional heat and do not require additional power. The consolidated processing strength of multiple cores enables next-generation systems and opens up new possibilities for very high-performance blade servers.

The reduction of bottlenecks among processors and system components in AMD’s Direct Connect architecture, for example, makes possible more efficient use of current system resources as well as tomorrow’s high-end components (Figure 2). In particular, dual-core processing is well suited to large clusters. The processing capability of two cores on one chip makes possible server and workstation consolidation. The efficiency of this technology also opens up a new level of high-performance computing and the flexibility to design more innovative solutions that directly address specific customer needs.

The quest for greater performance in embedded and high-performance applications has pushed systems manufacturers to incorporate PCI slots into blades. PCI expansion slots are being implemented in newer blade servers. Higher-performing PCI-X clock speeds up to 133 MHz pump throughput up into the gigabyte/second range. This speedy bus is ideal for critical cards such as frame grabbers and higher-end control cards. PCI-compatible graphics cards can now be added directly to the server for use in backracking, machine vision and imaging implementations.

PCI-X is viewed by many as a logical way to combine more robust bandwidth and greater cost efficiency in data-intensive environments. Applications range from medical imaging to industrial controls to virtual private networking, as well as communications systems and storage area network products such as clustered servers. A PCI-X solution usually offers 32-bit or 64-bit modes and is backward compatible with existing PCI configurations.

The ability to house multiple OSs, previously a convenience, is quickly becoming a requirement in high-performance applications. Within a single rack the newer blades can each run a different OS, either in single or dual boot mode, or, even more efficiently, two concurrent virtualized OSs. Ideally, a blade would provide interoperability with all major OS offerings, including Windows Server and XP Pro, RedHat, SUSE, Fedora Core Linux, and, in some cases, even Solaris 10. Off-the-shelf software applications could be integrated seamlessly and most custom applications could be installed with little or no reconfiguration.

As blades become smaller and more efficient, low-power processors and innovative cooling techniques are emerging that minimize power and cooling requirements while increasing maximum processor core density. A blade can further reduce wattage with a combination of the proper management of power requirements and the customization of hardware configurations to meet the needs of the application and task. A mix of active and passive cooling techniques allows form-factors to be reduced and blades to be housed in much smaller rooms than required previously.