FCAT Frametime analysis

Frametime and latency performance

With FCAT 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. 

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?

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 often matters more than frametime measurements. 

Above an FCAT plot of latency relative to FPS in percentiles. We use the Geforce GTX 1070 and a Radeon R9 Fury. I also added a 380X and GeForce GTX 960 (2GB) for a bit of scaling with mainstream cards. 

I often get asked the question why we do not include the faster Fury X here, well FCAT is dependant of a DVI monitor output, and AMD is not implementing them any more on their reference products. Only board partner cards release DVI enabled products. Hence the R9 Fury we use is the STRIX from ASUS, as it has a proper DVI output connector. So at 50% you could consider to be the average frame-rate. The cards are nice and close and cuddly to another. The plot is based on the first 31 seconds measured in the benchmark. 

Frame Pacing / Frametime

Above a the frame-time results plot of the test run @ 2560x1440 (WQHD) performed with a GeForce GTX 1070 in 2560x1440 (WQHD). That's very nice rendering really. You can see one HUGE spike, that actually is a massive explosion in-game and split-second that does drop the framerate during the impact, so don't worry about it. 
 

For AMD the FURY, we see similar perfect behaviour really. This is looking very good. For AMD the second explosion (mortar or something) dropped closer by hence the bigger spike. Again that is the game engine, not an anomaly. You can look at the video above which is the FCAT measurement, where the camera shakes .. that's it.

And once we overlay all cards we see that both AMD and NVIDIA perform precisely the same frametime and experience wise. I have no concerns here whatsoever.