Those humming racks of servers are the engine of the datacenter, and these days they’re hungry for power, and generating a lot of heat. The cost of electricity to power and cool the datacenter is now a significant part of any IT group’s budget, sometimes exceeding in one year the purchase price of the actual equipment, according to a Clipper Group study.

But relief may be at hand. Over the past year, Intel (which will be followed soon by AMD) has introduced quad-core processors, which deliver tremendous performance to industry-standard servers, while dramatically improving power efficiency.

Clock speeds are so “over”

Not so long ago, a server’s performance was measured by the clock speed of its CPU. The catch was, the faster the clock speed, the more energy—frequently upwards of 150 watts per CPU—was consumed. The incidental costs quickly racked up, as underutilized single-application servers proliferated, consuming valuable datacenter real estate, adding to administrative overhead.

Dual-socket quad-core systems, with four processors in each of two sockets, provide overall performance, and performance-per-watt increases within the same power envelope, offering customers a compelling solution for enterprise applications. The cores of these multi-socket designs run cooler and slower, and therefore require less power to cool as well.

Two-socket servers are the sweet spot

Besides their power saving attributes, multi-socket systems deliver the price-performance enterprises need to build a truly scaled-out architecture. The need for 4-socket and above systems is expected to decline due to the performance (and performance-per-watt) of 2-socket quad-core systems.

According to IDC, overall growth of 2-socket x86 systems over the past five years has been approximately 14%, while 4-socket system growth has declined 3.4% overall. Two-socket servers with multi-core processors offer similar, if not superior, performance at half the cost in key industry-standard benchmarks.

“Two-socket multi-core systems are the sweet spot of today’s market,” says Glenn Keels, senior manager of Dell Server and Systems Management marketing. “These servers can run more than 75 percent of enterprise applications, while delivering excellent availability and scale-out features like redundant networking and power supplies.”

While four-socket systems might be justified for especially demanding or memory-intensive applications, every socket must be powered whether it’s used or not. It is estimated that less than 30% of 4-socket systems in use have populated memory exceeding the capacity of standard 2-socket systems.

In any event, multi-socket technology quells the argument that proprietary scale-up RISC and UNIX solutions are necessary for enterprise computing. Right now, two-socket systems deliver the best performance-per-watt.

Choosing the right form factor

Two-socket quad-core systems are packaged in three ways: rack systems, blades and towers. Which one is right for you? There’s no simple answer, since many factors come into play. Consider your organization’s infrastructure objectively: application, deployment, power and performance requirements should drive your decision.

Blades have a well-deserved reputation for economical power consumption, since several blades share a single power supply. If a blade fails or indicates a problem, replacing it is simple and quick. The simplified cabling, excellent serviceability and small footprint of blade systems deliver excellent TCO, while their shared components improve reliability.

However, a fully loaded cabinet of blades uses an enormous amount of electricity—more than many datacenters can supply to a compact area. The high density of this deployment can create hot spots in the datacenter, straining cooling capability and perhaps requiring an expensive power build-out.

Blades also have a proprietary architecture—you can’t mix blades from different vendors within a chassis. Many companies are reluctant to tie themselves to a single vendor solution. Further, in some enterprises, business groups expect to have their own dedicated servers to host applications—the fungible nature of blade systems is not well-suited to that culture.

The limitations of blade systems explain why their market share is holding at just 30 percent. Most of the two-socket servers being deployed today are general purpose rack servers, which provide better usable density in most cases than blades.

“Look first to two-socket mainstream rack systems” says Keels. “Don’t start the discussion with more proprietary solutions, such as blades or 4+ socket systems.”

Dell quad-core servers

Dell’s enterprise-class 64-bit quad-core servers are designed to deliver the best performance and flexibility for demanding IT environments. Dell is partnering with leading vendors like Microsoft, Oracle, SAP, Red Hat, VMware and Novell, which offer multi-threaded applications and operating systems that take advantage of the full benefits of multi-core computing.

Dell is committed to developing multi-core technology across all server products, focusing on the complete platform, including processors, memory and I/O.