AMD Athlon 64 X2 65nm Brisbane-Core

At the end of 2006, AMD announced the availability of processors built using the company's 65nm manufacturing process, which is first being implemented with the Athlon 64 X2 product line. The move to 65nm brings a number of advantages for both AMD and consumers. From AMD's standpoint, the more advanced manufacturing process allows for more processors to be produced per wafer, therefore improving manufacturing efficiency and in turn profit margins. Ultimately, the aim is to let this savings trickle down into retail channels, lowering AMD's costs and potentially the cost of the X2 lines across the board. The move to 65nm also lays the foundation for future, native-quad core processors that would be too costly to produce at 90nm.

With this transition, cost is a major factor, of course, but not just from a manufacturing perspective.  With the change over to 65nm, AMD has also sharpened their focus on power consumption and energy efficiency, which translates to lower operating costs as well.  What AMD has not worked into the transition are any core performance enhancements.  The goal was instead a more energy efficient processor that consumes less power and produces less heat, while maintaining a similar performance level as their 90nm processors.  This, in turn, should translate to higher performance per watt than the 90nm design.  However, since its initial release, the performance impact of changes introduced with the new 65nm CPUs has come into question.

Since its release in December, several major publications have confirmed the differences in power consumption and performance between AMD's 65nm and 90nm cores.  Additionally, in testing, some have noted increased cache latencies resulting in a slight decrease in performance in some tests.  In our coverage of the 65nm Athlon X2, naturally we'll compare power consumption and performance at the outlet between the 65nm and 90nm processor to quantify the differences. Then, we'll take a moment to run a series of performance tests to assess whether the higher cache access latencies have an impact on performance, or whether in the end they turn out to be much ado about nothing.

Specifications of the 65nm AMD Athlon 64 X2 "Brisbane"

Frequency / Cache Sizes: 5000+ 2.6GHz w/ 512KB L2 cache-per-core Frequency / Cache Sizes: 4800+ 2.5GHz w/ 512KB L2 cache-per-core Frequency / Cache Sizes: 4400+ 2.3GHz w/ 512KB L2 cache-per-core Frequency / Cache Sizes: 4000+ 2.1GHz w/ 512KB L2 cache-per-core L1 Cache Sizes: Each core has its own 64K of L1 instruction and 64K of L1 data cache (256KB total L1 per processor) CPU to Memory Controller: same as CPU core frequencies Memory Controller: Shared integrated 128-bit wide memory controller Types of Memory: Unbuffered DDR2: PC2 6400 (800MHz), PC2 5300 (667MHz), PC2 4200 (533MHz), PC2 3200 (400MHz) HyperTransport Links: 1 HyperTransport Spec: 2GHz (2x 1000MHz / DDR) Effective data bandwidth: 14.4 GB/sec [8GB/sec x1 HyperTransport link + 6.4GB/sec memory bandwidth] Packaging: Socket AM2 (940-pin organic micro-PGA)

Fab location: AMD's Fab 30 wafer fabrication facility in Dresden, Germany Process Technology: 65nm (.065-micron) Silicon on Insulator (SOI) Approximate Transistor count: 153.8 million Approximate Die Size: 126 mm2 Nominal Voltage: 1.25 - 1.35 V Max Thermal Power: 65W Max Ambient Case Temp: 49 - 72 degrees Celsius

AMD's base pricing structure for the newer 65nm based Athlon 64 X2's