Frametime and latency performance
Frametime and latency performance
With a benchmark technology called FCAT on the following two pages, we will look into Frame Experience Analysis. Basically with the charts shown we are trying to show you graphics anomalies like stutters and glitches in a plotted chart. Lately there has been a new measurement introduced, latency measurements. Basically it is the opposite of FPS.
- FPS mostly measures performance, the number of frames rendered per passing second.
- Frametime AKA Frame Experience recordings mostly measures and exposes anomalies - here we look at how long it takes to render one frame. Measure that chronologically and you can see anomalies like peaks and dips in a plotted chart, indicating something could be off.
Frame time in milliseconds |
FPS |
8.3 | 120 |
15 | 66 |
20 | 50 |
25 | 40 |
30 | 33 |
50 | 20 |
70 | 14 |
We have a detailed article (read here) on the new FCAT methodology used, and it also explains why we do not use FRAPS anymore. Frametime - Basically the time it takes to render one frame can be monitored and tagged with a number, this is latency. One frame can take say 17 ms. Higher latency can indicate a slow framerate, and weird latency spikes indicate a stutter, jitter, twitches; basically anomalies that are visible on your monitor.
What Do These Measurements Show?
Basically, what these measurements show are anomalies like small glitches and stutters that you can sometimes (and please do read that well, sometimes) see on screen. Below I'd like to run through a couple of titles with you. Bear in mind that Average FPS matters more than frametime measurements.
Frame Pacing / Frametime - Single GPU
Above a plotted frame-time results of the test run @ 2560x1440 performed with a single Radeon R9 Fury (4GB) in 2560x1440. It is refreshing to see such clean FCAT results these days, no (micro) stutters with the are detected card at WHQD. Have a look below and you will observe similar behaviour from Nvidia:
Above a GeForce GTX 980 in green at 2560x1440. This test run lasts roughly 30 seconds. Overall this is as smooth as the Radeon R9 Fury with very similar characteristics. However the Fury after 15 seconds shows higher latency and thus drops in framerate.
And now we combined the results. As you can see, very similar characteristics for both vendors. Micro-stuttering is not even topic of discussion.
We tested here in the intro Ascension level where you walk towards the mountain you'll need to climb. When the wind starts to gust more snow is entering the scene, that's the point where the Radeon R9 Fury is having a rougher time as you can see in the frametime chart.