Hmm. Where to begin? Probably early last month, when we discovered some performance problems with the Radeon HD 7950 in recent games using our newfangled testing methods, which focus on frame rendering times rather than simple FPS averages. Eventually, AMD acknowledged the problem and pledged to address the issues of high-latency frames in a series of driver updates.
Happily, we didn't have to wait long for the first update in that series. Within a day or two, AMD provided us a Catalyst 13.2 beta driver that includes fixes intended to improve frame rendering times in several of the DirectX 9 based games in our test suite: Skryim, Borderlands 2, and Guild Wars 2. Our report on this driver was delayed by a couple of factors, including our attendance at CES and an apparent incompatibility between this beta driver and our Sapphire 7950 card.
We still haven't figured out the problem with the Sapphire card, but we ultimately switched to a different 7950, the MSI R7950 OC, which allowed us to test the new driver. The results on the following pages come from the MSI card. As you'll see, its performance under the Catalyst 12.11 beta drivers is very similar to what we saw from the Sapphire, with the same latency profile and the same intermittent spikes caused by high-latency frames.
We have several interesting developments to discuss, including the nature of the changes AMD has made to the Cat 13.2 beta driver, but first, let's take a look at our test results, which should help illustrate some of our points.
Since it's been a while and one of the cards has changed, we'll do a quick recap of our test configs before moving on.
Our testing methods
As ever, we did our best to deliver clean benchmark numbers. Our test systems were configured like so:
|Chipset||Intel X79 Express|
|Memory size||16GB (4 DIMMs)|
DDR3 SDRAM at 1600MHz
|Memory timings||9-9-11-24 1T|
|Chipset drivers||INF update
Rapid Storage Technology Enterprise 188.8.131.521
with Realtek 184.108.40.20662 drivers
|Hard drive||Corsair F240 240GB SATA|
|Power supply||Corsair AX850|
|Zotac GTX 660 Ti AMP!||GeForce 310.54 beta||1033||1111||1652||2048|
|MSI R7950 OC||Catalyst 12.11 beta 8||880||-||1250||3072|
|MSI R7950 OC||Catalyst 13.2 beta||880||-||1250||3072|
Thanks to Intel, Corsair, and Gigabyte for helping to outfit our test rigs with some of the finest hardware available. AMD, Nvidia, and the makers of the various products supplied the graphics cards for testing, as well.
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.
In addition to the games, we used the following test applications:
- Fraps 3.5.9
We used the Fraps utility to record frame rates while playing either a 60- or 90-second sequence from the game. Although capturing frame rates while playing isn't precisely repeatable, we tried to make each run as similar as possible to all of the others. We tested each Fraps sequence five times per video card in order to counteract any variability. We've included frame-by-frame results from Fraps for each game, and in those plots, you're seeing the results from a single, representative pass through the test sequence.
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.