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Batman: Arkham city
For this test, we threw down with a pack of the Joker's henchmen in an all-out brawl for 90 seconds.

We tested at 6048x1200 with the detail levels maxed, DirectX 11 effects enabled, and antialiasing at its highest setting.

Now, we should preface the results below with a little primer on our testing methodology. Along with measuring average frames per second, we delve inside the second to look at frame rendering times. Studying the time taken to render each frame gives us a better sense of playability, because it highlights issues like stuttering that can occur—and be felt by the player—within the span of one second. Charting frame times shows these issues clear as day, while charting average frames per second obscures them.

For example, imagine one hypothetical second of gameplay. Almost all frames in that second are rendered in 16.7 ms, but the game briefly hangs, taking a disproportionate 100 ms to produce one frame and then catching up by cranking out the next frame in 5 ms—not an uncommon scenario. You're going to feel the game hitch, but the FPS counter will only report a dip from 60 to 56 FPS, which would suggest a negligible, imperceptible change. Looking inside the second helps us detect such skips, as well as other issues that conventional frame rate data measured in FPS tends to obscure.

We're going to start by charting frame times over the totality of a representative run for each system—though we conducted five runs per system to be sure our results are solid. These plots should give us an at-a-glance impression of overall playability, warts and all. (Note that, since we're looking at frame latencies, plots sitting lower on the Y axis indicate quicker solutions.)

Frame time
in milliseconds
FPS rate
8.3 120
16.7 60
20 50
25 40
33.3 30
50 20

The Gigabyte GTX 680 OC suffers from more frequent latency spikes than the Asus card. With few exceptions, the magnitude of those spikes is relatively low. The GTX 680's frame latencies rarely exceed 40 milliseconds, which means the corresponding frame rate doesn't often dip below 25 FPS. Although the 7970 has fewer latency spikes, the magnitude of those spikes is much greater, often hitting 50-60 ms. That works out to a frame rate of just 17-20 FPS.

We can slice and dice our raw frame-time data in other ways to show different facets of the performance picture. Let's start with something we're all familiar with: average frames per second. Though this metric doesn't account for irregularities in frame latencies, it does give us some sense of typical performance.

The Gigabyte card has a clear lead in the FPS arena, but we're not done yet. We can demarcate the threshold below which 99% of frames are rendered. The lower the threshold, the more fluid the game. This metric offers a sense of overall frame latency, but it filters out fringe cases.

Of course, the 99th percentile result only shows a single point along the latency curve. We can show you that whole curve, as well. With single-GPU configs like these, the right hand-side of the graph—and especially the last 5% or so—is where you'll want to look. That section tends to be where the best and worst solutions diverge.

In our frame-time plots, the Asus HD 7970 TOP exhibits more severe latency spikes than the Gigabyte card. Those deviations are illustrated nicely by our percentile curves, which show the 7970's frame times rising sharply for the last ~3% of frames. The GTX 680's frame times also increase for the final few percent, but they mostly stay below 40 milliseconds.

Finally, we can rank solutions based on how long they spent working on frames that took longer than 50 ms to render. The results should ideally be "0" across the board, because the illusion of motion becomes hard to maintain once frame latencies rise above 50-ms or so. (50 ms frame times are equivalent to a 20 FPS average.) Simply put, this metric is a measure of "badness." It tells us about the scope of delays in frame delivery during the test scenario.

The 7970 spends nearly twice as long as the GTX 680 working on frames that take longer than 50 milliseconds to render. That said, we're looking at less than 0.6 seconds over the course of a 90-second session. Arkham City feels smooth on both of these cards, which is impressive considering the six-megapixel resolution and maxed detail settings we used for testing.