Test notes
Speaking of straying from formula, we decided to try out some new games in different genres for this review, some with support for Nvidia's exclusive PhysX API and some with support for the Radeon-exclusive DirectX 10.1. As you may know, we've generally found this latest generation of GPUs from AMD and Nvidia to be very evenly matched in terms of features and image quality, leaving price and performance as the primary deciding factors between the two brands. Perhaps looking at a broad scope of games and putting PhysX and DX10.1 into the mix will give us some new insights. Where possible, we've tested both with and without PhysX and DX10.1, to demonstrate the impact of these technologies.

Branching out into a bunch of new games tends to be time-consuming, so we decided to focus on the Radeon HD 4770 vs. GeForce 9800 GT match-up for the bulk of our testing. In order to also give you some broader context, we've included scores from 3DMark and Far Cry 2, along with power and noise testing, for a range of video cards. Those numbers were drawn from our Radeon HD 4890 vs. GeForce GTX 275 review and include results from older driver revisions, as noted in that article's testing methods section. These scores should be decent enough as point of reference, but be aware that the comparison to the newer cards and drivers may not be perfectly exact.

For the rest of our testing, we used FRAPS to capture frame rates while playing the games. We typically recorded frame rates over five gameplay sessions of 60 seconds each. We averaged the mean frame rate from each of the five sessions, and we also reported the median of the minimum frame rates from those sessions. This method of testing will inevitably introduce some variability, but we believe averaging five sessions ought to be sufficient to give us reliable results. However, for two games, Sacred 2 and Dawn of War II, we were not confident the 60-second window was long enough given the variability of the games' performance over time, so we extended the window to five minutes and still recorded five sessions.

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:

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.

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:

• Sacred 2: Fallen Angel 2.40.0 build 1551
• Warhammer 40,000: Dawn of War II 1.2.1
• Tom Clancy's HAWX 1.01
• Mirror's Edge 1.01
• World of Warcraft trial version
• Far Cry 2 1.02
• Left 4 Dead
• 3DMark Vantage 1.0.1
• FRAPS 2.9.8

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.