Our testing methods
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:

Processor Core 2 Extreme QX9650 3.0GHz
System bus 1333MHz (333MHz quad-pumped)
Motherboard Gigabyte GA-X38-DQ6
BIOS revision F9a
North bridge X38 MCH
South bridge ICH9R
Chipset drivers INF update 8.3.1.1009
Matrix Storage Manager 7.8
Memory size 4GB (4 DIMMs)
Memory type 2 x Corsair TWIN2X20488500C5D
DDR2 SDRAM at 800MHz
CAS latency (CL) 5
RAS to CAS delay (tRCD) 5
RAS precharge (tRP) 5
Cycle time (tRAS) 18
Command rate 2T
Audio Integrated ICH9R/ALC889A
with RealTek 6.0.1.5618 drivers
Graphics
Radeon HD 2900 XT 512MB PCIe
with Catalyst 8.5 drivers
Asus Radeon HD 3870 512MB PCIe
with Catalyst 8.5 drivers
Radeon HD 3870 X2 1GB PCIe
with Catalyst 8.5 drivers
Radeon HD 4850 512MB PCIe
with Catalyst 8.501.1-080612a-064906E-ATI drivers
MSI GeForce 8800 GTX 768MB PCIe
with ForceWare 175.16 drivers
XFX GeForce 9800 GTX 512MB PCIe
with ForceWare 175.16 drivers
XFX GeForce 9800 GX2 1GB PCIe
with ForceWare 175.16 drivers
GeForce GTX 260 896MB PCIe
with ForceWare 177.34 drivers
GeForce GTX 280 1GB PCIe
with ForceWare 177.34 drivers
Hard drive WD Caviar SE16 320GB SATA
OS Windows Vista Ultimate x64 Edition
OS updates Service Pack 1, DirectX March 2008 update

Thanks to Corsair for providing us with memory for our testing. Their quality, service, and support are easily superior to no-name DIMMs.

Our test systems were powered by PC Power & Cooling Silencer 750W power supply units. The Silencer 750W was a runaway Editor's Choice winner in our epic 11-way power supply roundup, so it seemed like a fitting choice for our test rigs. Thanks to OCZ for providing these units for our use in testing.

Unless otherwise specified, image quality settings for the graphics cards were left at the control panel defaults. Vertical refresh sync (vsync) was disabled for all tests.

We used the following versions of our test applications:

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.