Test notes
Since we have a Socket AM2 processor article in the works, we've limited the bulk of our testing to chipset features and peripherals. Expect more extensive application performance results for a wide range of Socket AM2 processors soon.

Our performance testing focuses on the CrossFire Xpress 3200 for AM2 and the nForce 590 SLI, but we've also thrown in a couple of Socket 939 platforms for reference. Those platforms are based on the CrossFire Xpress 3200/ULi M1575 and nForce4 SLI X16 chipsets, respectively. Note that in the graphs, our Socket 939 CrossFire Xpress 3200 appears as the "CrossFire Xpress 3200," while the Xpress 3200 for AM2 is listed as the "CrossFire Xpress 3200 AM2."

In order to ensure comparable results between platforms, we tested the Socket 939 boards with an Opteron 180, which runs at 2.4 GHz, and we tested the AM2 platforms with an Athlon 64 FX-62 underclocked to 2.4 GHz. Both chips are dual-core K8 processors with 1MB of L2 cache, and for all intents and purposes, the Opteron 180 is equivalent to the Athlon 64 X2 4800+. The underclocked Athlon 64 FX-62 is also equivalent to the AM2 version of the X2 4800+. In order words, this should be a like-to-like match of processors between Socket 939 and Socket AM2, leaving the chipsets on equal footing. We also used relatively relaxed timings for our Socket 939 platform's DDR memory because the DDR2 we used for testing the AM2 boards would only run at less aggressive 5-5-5-12 timings.

To prevent BIOS- or motherboard-specific memory timing defaults from skewing our results, we made sure that as many memory timings as possible were equalized across our respective Socket 939 and AM2 platforms. We also disabled LinkBoost on the nForce 590 SLI because it's only compatible with the GeForce 7900 GTX. A GeForce 7900 GTX was used in our test systems, but as much as manufacturers would like us to evaluate entire platforms, today we're targeting the chipset. To indulge those wondering whether LinkBoost really does make a difference, we've snuck a few extra results into our multi-GPU performance tests.

Our testing methods
All tests were run at least twice, and their results were averaged, using the following test systems.

Thanks to Corsair for providing us with memory for our testing. 2GB of RAM seems to be the new standard for most folks, and Corsair hooked us up with some of its 1GB DIMMs for testing.

Our test systems were powered by OCZ PowerStream power supply units. The PowerStream was one of our Editor's Choice winners in our latest PSU round-up.

We used the following versions of our test applications:

• WorldBench 5.0
• trq4demo1 demo
• Half-Life 2: Lost Coast with trcoast1 demo
• FutureMark 3DMark06 Build 1.0.2
• F.E.A.R. 1.04
• TCD Labs HD Tach v3.01
• Futuremark 3DMark06 Build 1.02
• RightMark 3D Sound 2.2
• NTttcp
• Intel iPEAK Storage Performance Toolkit 3.0
• Intel IOMeter v2004.07.30

The test systems' Windows desktop was set at 1280x1024 in 32-bit color at an 85Hz screen refresh rate. Vertical refresh sync (vsync) was disabled for all tests. Most of the 3D gaming tests used the Medium detail image quality settings, with the exception that the resolution was set to 640x480 in 32-bit color.

All the tests and methods we employed are publicly available and reproducible. If you have questions about our methods, hit our forums to talk with us about them.