If you’ve read any our video card reviews for the last few months, you’ve probably noticed that we have included frame time results using FCAT in our performance data. For single GPU configurations, the FCAT/frame time data was interesting to look at, but it didn’t show any major issues across a wide swath of both AMD and NVIDIA built GPUs. Multi-GPU configurations, however, were a completely different story altogether. Way more often than not NVIDIA SLI-based solutions offered smoother, more consistent frame times across the board, whereas AMD CrossFire-based solutions suffered from erratic frame pacing, which resulted in wild swings in frame times.
A few months back, AMD promised the tech press that the company was working on a new driver that would resolve frame pacing issues with CrossFire configurations and that said driver would be made available this summer. It turns that today is the day AMD makes good on their promise. The just released AMD Catalyst 13.8 beta drivers enable frame pacing control for DirectX 10 and 11 applications. After installing the driver, the controls are made available right in the 3D Application Settings section of the Catalyst Control Center.
We’ve had the Catalyst 13.8 beta drivers in hand for a couple of days now and did some quick testing with a quartet of games to see how frame pacing affected frame times and frame rates. We used a Radeon HD 7990 for these tests, since CrossFire is essential for the card to function properly. AMD frame pacing issues with CrossFire left us hesitant to recommend the card, despite the fact that it had huge performance potential. And with that, on to the results...
These results were obtained using only the new Catalyst 13.8 beta driver, with frame pacing enabled and disabled. As you can see in most of the plots, enabling frame pacing has a huge impact on frame time consistency. Frame times are all over the map with Alien vs. Predator with frame pacing disabled, but with it on, the performance is dramatically more consistent. Frame times are much more consistent in Sleeping Dogs as well. Bioshock Infinite didn’t suffer nearly as bad without frame pacing, but it too showed some improvement. Hitman Absolution, however, while significantly improved, still suffers from some frame pacing issues.
Our quick look at the drivers definitely reveals some very real improvements. Smoother frame delivery is all well and good, but not if it causes frame rates to tank, so we did some testing in that regard as well.
As you can see, frame rates are hardly affected by enabling/disabling frame pacing in the Catalyst 13.8 betas. Technically, performance was down ever so slightly across the board, but the deltas are tiny enough to be insignificant. The only frame rate issue we observed in our limited tested with was Sleeping Dogs, which showed a major drop in its minimum frame rate. Hopefully that’s something AMD will address in a future update.
Though this driver shows real promise, we must point out that AMD’s frame pacing mechanism is still a work in progress. Here’s what AMD had to say about the Catalyst 13.8 betas:
- This phase 1 only, in which we’re addressing DX10 and 11 apps, resolutions up to, including 2560x1600
- For Phase 2, we’ll be addressing resolutions above 2560x1600, DX9 and OpenGL apps
- This feature is turned on by default in the driver, but you have the ability to turn it on and off, on a per-application basis
- This driver has full support now for OpenGL 4.3 feature set and has support for UCPs and CAPs
While the Catalyst 13.8 beta drives don’t address every game across any possible resolution, they should help the vast majority of the market, running a single monitor at a resolution up to and including 2560x1600. DirectX 9 support would be nice, but since they’re typically less taxing, they’re not likely to be GPU bound on a higher-end CrossFire setup, so the benefits of enabling frame pacing are less impactful.
Ultimately, AMD is on the right track and just make CrossFire and CrossFire-dependent products like their flagship Radeon HD 7990 more attractive. Kudos to AMD for making good on their promise to deliver a drive this summer. You'll be able to grab the Catalyst 13.8 beta drives here should you want to give them a try. (The like should be live shortly.)