Our testing methods
You'll notice the presence of a CPU marked "Core 2 4MB 1.86GHz" in our results. That's actually a Core 2 Extreme X6800 chip that I've clocked down to the same speed as the Core 2 Duo E6300. I wanted to see how the move from 4MB of L2 cache to 2MB impacts performance, so I set up this clock-for-clock comparison against the E6300.

Please note that the two Pentium D 900-series processors in our test are actually a Pentium Extreme Edition 965 chip that's been set to the appropriate core and bus speeds and had Hyper-Threading disabled in order to simulate the actual products. Similarly, our Socket AM2 versions of the Athlon 64 X2 4800+, 4600+, and 4200+ are actually the Athlon 64 FX-62 and X2 5000+ clocked down to the appropriate speeds, and the Core 2 Duo E6600 is actually an underclocked Core 2 Extreme X6800. The performance of our "simulated" processor models should be identical to the actual products.

Also, I've placed asterisks next to the memory clock speeds of the Socket AM2 test systems in the table below. Due to limitations in AMD's memory clocking scheme, a couple of these systems couldn't set their memory clocks to exactly 800MHz.

As ever, we did our best to deliver clean benchmark numbers. Tests were run at least three times, and the results were averaged.

Our test systems were configured like so:

Thanks to Corsair and Crucial for providing us with memory for our testing. Both of them provide products and support that are far and away superior to generic, no-name memory.

Also, all of our test systems were powered by OCZ GameXStream 700W power supply units. Thanks to OCZ for providing these units for our use in testing.

The test systems' Windows desktops were set at 1280x1024 in 32-bit color at an 85Hz screen refresh rate. Vertical refresh sync (vsync) was disabled.

We used the following versions of our test applications:

• SiSoft Sandra 2007.5.10.98 64-bit
• CPU-Z 1.33
• Compiled binary of C Linpack port from Ace's Hardware
• POV-Ray for Windows 3.6.1 64-bit
• SMPOV 4.6
• Cinebench 9.5 64-bit Edition
• LAME MT 3.97a 64-bit
• Windows Media Encoder 9 x64 Edition
• Sphinx 3.3
• picCOLOR 4.0 build 561 64-bit
• The Elder Scrolls IV: Oblivion 1.1
• Battlefield 2 1.22
• Quake 4 1.2 with trq4demo5
• FEAR 1.03
• Unreal Tournament 2004 v3369 and 3369 64-bit Edition with trdemo1
• 3DMark06 1.0.2
• WorldBench 5.0

The tests and methods we employ are generally publicly available and reproducible. If you have questions about our methods, hit our forums to talk with us about them.