Advanced Micro Devices on Monday unveiled its first “highly-efficient” AMD Opteron processors with four processing engines. The new chips feature lowered power consumption, but may not necessarily offer unprecedented performance-per-watt ratio due to relatively low clock-speeds and disputable way of measuring power consumption. Still, they provide low-power quad-core AMD chip options to the company’s clients.

“Our new Quad-Core AMD Opteron HE processors were designed to help datacenter managers who see power consumption and virtualization as the keys to solving their overall performance equation,” said Randy Allen, corporate vice president and general manager, server and workstation division, AMD.

The new chips for dual processor (DP) machines from AMD are quad-core Opteron models 2344 HE (1.70GHz), 2346 HE (1.80GHz) and 2347 HE (1.90GHz), whereas for multi-processor (MP) machines AMD unveiled quad-core 2346 HE (1.80GHz) and 2347 HE (1.90GHz) chips. All the central processing units (CPUs) unveiled feature so-called ACP of 55W, which is considerably lower compared to existing quad-core AMD Opteron processors.

AMD’s average CPU power consumption is a way of measuring power consumption of processing engines within AMD Opteron chips. Since modern microprocessors have built-in memory controller as well as HyperTransport controllers in addition to processing engines, AMD claims that declaring ACP instead of thermal design power (TDP, the amount of heat that cooling solution needs to dissipate) better reflects actual power consumption of its processing cores and allows to fairly compared power consumption of Intel Corp.’s (which have no memory controller inside) and AMD’s processors (which do not require complex core-logic with memory controller).

According to AMD’s estimates, microprocessors with 55W ACP may have up to 79W TDP.

“These new processors which feature AMD’s advanced power management and virtualization innovations offer a compelling platform for power-conscious datacenter managers who are changing the way they think about performance,” Mr. Allen said.

Intel’s latest low-power quad-core chips for DP market are Intel Xeon L5420 and L5410 chips that operate at 2.50GHz and 2.33GHz, respectively. Both central processing units utilize 1333MHz processor system bus (PSB) and feature 12MB of level-two cache. The new low-voltage Xeon processors are intended for DP servers or workstations and have 50W TDP. Thermal design power of Intel’s 5000/5100-series memory controller hub (MCH) is 23W – 30W depending on actual configuration.

Intel also ships a variety of quad-core chips for MP servers with relatively low power consumption, including L7310 (1.60GHz), L7320 (2.13GHz), L7330 (2.40GHz) and L7340 (2.40GHz) with 80W TDP as well as L7345 (1.86GHz) chip with 50W. Thermal design power of Intel’s 7300-series chipset’s MCH for MP machines is 40W or 47W depending on memory configuration.

Even though quad-core AMD Opteron HE-based MP systems may be more power efficient than machines powered by Intel Xeon 7300-series chips, the latter systems may provide generally higher performance. When it comes to DP systems, Intel-based machines are likely to offer considerably higher performance-per-watt ratio due to higher clock-speeds amid similar thermal design power of Intel’s CPU with MCH with AMD’s CPUs.

AMD Opteron 2347 HE, 2346 HE and 2344 HE cost $377, $255 and $209, respectively, in 1000-unit quantities. Designed for MP machines, AMD Opteron processors 8347 HE and 8346 HE are priced at $873 and $698, respectively.