Results: Battlefield 4
Our results in Battlefield 4 change dramatically compared to the original story, which showed barely any scaling at all with a second Radeon R9 295X2. As you can imagine, that first round of numbers seemed implausible, and we retested multiple times across several drive images. Consistently, we ended up with a frame rate over time chart that largely tracked a single 295X2, but spiked and dipped much more severely.
After that piece went live, AMD shared its own results with us, prompting me to revisit this game (and indeed all of the others as well). At one point, I noticed that, after installing the Catalyst beta package on the two-card system, CrossFire was reported as enabled, yet scaling was off in every test run. Then, after clicking the “Something requires your attention” pop-up, the technology suddenly showed up disabled. Between this and another apparent issue where turning CrossFire on or off caused the screen to go dark, necessitating a soft-reboot, there appear to be a couple of minor software bugs.
At any rate, toggling CrossFire off and back on seemed to help, yielding more impressive scaling figures. FCAT says an average of 84 FPS. Fraps says 84 FPS as well. It’s a match that yields a 75% boost with a second card.
Charting frame rate over time exposes more dramatic changes in instantaneous performance, with dips to 50 FPS and peaks up to 100 FPS. Even at its slowest, however, an array of Radeon R9 295X2 cards are faster than the fastest competition.
It’d be easy to call that the perfect example of why you’d spend $3000 on four Hawaii GPUs. But it’s not. There’s an experiential element that doesn’t show up in the average frame rate or frame rate over time charts, and that’s stutter. The stutter is so much more apparent with four GPUs than two, and I’d rather have the smoother game at lower frame rates than whatever two Radeon R9 295X2s give you. Battlefield 4 suffers from this more severely than any other title in our suite.
Nvidia’s GeForce GTX 780 Ti actually shows up in last place due to its 3 GB of memory per GPU, which isn’t enough for a smooth experience in this game. I’ve already done everything I can to dissuade you from 3 GB cards for 3840x2160, and that story remains intact.
More surprising to me is that we don’t get the sense of choppiness by looking at frame time variance. Typically a 95th percentile result in the 6 ms range isn’t bad.
Putting frame time variance on a line chart shows where there’s a ton of difference between frames rendered by two GeForce GTX 780 Tis. You can see where the two Radeon R9 295X2s peek out from behind, though. And again, regardless of what the charts say, the stutter is impossible to ignore and all the more bothersome from three-grand worth of graphics cards.
