AMD Guns for Intel`s Nehalem with the Phenom II

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AMD brings lessons learned from Shanghai to create the 45nm Phenom II, a CPU bred for overclocking and high performance. But can it outperform Intel’s blazing Nehalem chip?

AMD’s venture into 45 nanometer technology has resulted in the next generation of Phenom, called Phenom II. With Phenom II, AMD aims to get back into speeds and feeds, hoping to offer a price/performance ratio that is just too hard for solution providers and end users to ignore. Initially, AMD will be shipping two versions of the Phenom II, a quad-core Phenom II X4 920 and Phenom II X4 940 due in January, offered at 2.8GHz and 3.0GHz, respectively.

Phenom II offers innovation beyond its 45nm design and higher clock speeds. This processor class offers increased L2/L3 cache, now measuring 8 Mbytes (L2+L3) along with AMD’s latest iteration of its proprietary “Cool ’n’ Quiet” technology, which promises additional energy savings by reducing power consumption by 40 percent when the CPU is idle. Other enhancements include the microcode and chip design that improve speed and reduce power consumption even further.

We put a 3.0Ghz Phenom II X4 940 through its paces to measure just how well this new $275 (£193) processor will perform. Our test platform consisted of an ASUS M3A78-T with 4 Gbytes of DDR2 RAM, and a CoolIT Systems Domino Liquid Cooling unit (liquid cooling is a must for our over clocking tests).

From a cost perspective, the Phenom II beats Intel’s Nehalem on two fronts. First, the X4 940 is priced at $275 (£193), while the Intel Core i7-965 EE (Nehalem) is priced at $999 (£700). Second, Nehalem requires more expensive DDR3 RAM over the Phenom II’s DDR2 RAM.

We used Passmark’s Performance Test V6.1 to collect CPU and memory scores. The X4 940 achieved a CPUMark score of 3348.6 and a MemoryMark score of 593.6. That is a significant improvement over the first generation Phenom 9950 (2.6Ghz), which only scored a CPUMark and Memory of 2811 and 470.9, respectively.

Yet the Phenom II can’t hold a candle to the top-of-the-line Intel Core I7 -965 EE, which scored a CPUMark of 7610.5 and a MemoryMark of 1179.8. But, one does have to consider that the Intel Core I7 -965 EE is almost four times the cost of the Phenom II. A more fair comparison would be between the $275 (£193) Phenom II and a comparably priced Nehalem, such as the $284 (£199) Intel Core i7-920. The i7-920 is a 2.66Ghz processor and scored a CPUMark of 5907, which is a significant step up from the Phenom II’s score of 3348.6. The i7-920’s MemoryMark score is 680.2, which still outpaced the Phenom II’s score of 593.6.

By all indications, Intel’s Core i7 CPUs can outperform anything in AMD’s Phenom II lineup, but AMD does have a trick up its sleeve: overclocking. Although AMD warns that overclocking may void the warranty, overclocking has become a somewhat common practice. The top-of-the-line Phenom II X4 940 is available as a “black edition,” which means that the clock multiplier is unlocked. That allows the CPU to be overclocked using AMD’s OverDrive utility. The Intel Core i7-920 is a locked CPU and cannot be overclocked. If someone wants to experiment with overclocking on a Nehalem CPU, only the top-of-the-line $999 (£700) Extreme Edition offers an unlocked multiplier.

How fast can the Phenom II perform? Surprisingly, if the proper cooling is used, the Phenom II can be overclocked by a significant amount. Some have reported that the Phenom II can be overclocked to as much as 6Ghz, when using liquid nitrogen cooling. But, liquid nitrogen and other advanced cooling methodologies are not practical in the real world, where the typical system builder relies on traditional air cooling.

We were able to test the Phenom II at speeds up to 3.9Ghz, but after hours of running CPU-intensive applications, we did encounter some instability, such as random system lockups and blue screens. However, at 3.6Ghz we had no stability problems whatsoever and ran the system for 16 hours under constant stability testing using the AMD Overdrive Utility. For our particular setup, 3.6Ghz seemed to be the sweet spot. At 3.6Ghz, the Phenom II offered a CPUMark score of 4800.6 and a MemoryMark Score of 820.2, a significant improvement over the performance found at 3Ghz. With better cooling and additional tweaking, higher performance should be attainable and prove to be reliable.

AMD’s Phenom II is a step in the right direction for the company and is a viable, low-cost alternative to Intel’s entry-level Nehalem processor.