Assassin’s Creed 3Our Assassin’s Creed 3 test involves a 60 second run through the Boston Harbor. Each run took a similar route, and was repeated five times. When a representative number of frames was found, we used one of those to evaluate the performance you see below.
The GeForce actually gets an extra option for Anti-aliasing, but we stuck with Very High for both. We’ll start with Frames per Second, to give you some context:
For your reference, we’ll leave this handy frame time/FPS conversion chart up at the top of each page:
|Frame Time (ms)||16.7||20||25||33.3||50|
Right off the bat, we see that the Radeon 7870 falls behind quite a bit in this game. Assassin’s Creed 3 is known to have frame rate issues with the Radeon – let’s see how this relates to frame delivery:
The lower FPS translates well here, with the GeForce 600 hovering around the 20ms mark, while the Radeon 7870 runs into some issues. Despite the lower performance, the Radeon is delivering some solid frame times, as is indicated by the ‘tight’ looking graph.
Another way to look at this data is to get an idea of what the worst case frame delivery time is like. In other words, if we leave out the top 99% fastest delivered frames, only looking at the slowest 1%, how bad does it get?
As is often the case, the 99th percentile frame time looks sort of like an inverted version of the FPS graph. This means that those ‘laggy parts’ you experience when playing Assassin’s Creed 3 drop to about 27ms on the GeForce 660 – or about “35 fps” – and 35ms on the Radeon 7870 – about “29 fps”.
Finally, we can look at how much time is spent over a certain threshold. Determining this threshold is completely subjective – one person might never want a game to go below 60 fps, while others are fine if it dips below that occasionally. This is a good way of showing that even when a benchmark runs at a certain “FPS” over the run, it can actually spend quite a bit of time running slower than the average. How much time depends on the game.
We will show as many thresholds as necessary – sometimes a game runs so fast, both charts would be zero.
Obviously we know both cards will spend most of the run delivering frames slower than 16.7 ms, but when we set the threshold to 33 ms, we see the major difference in performance. The Radeon 7870 spends 5 seconds out of 60 running slower than 30 FPS, while the GeForce 660 is there for under half a second total.