Frame Capture and Analysis Tools Reviewccokeman - April 1, 2013
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A tremendous amount of data is created during the capture and analysis process including charts that plot out the 95th and 99th percentile frame rates as well as charts that show the observed FPS versus the FRAPS FPS. Below are some representations of the data presented showing that yes, even with the latest drivers AMD is struggling with some frame time issues that drive the FPS delivered down to a level below that reported by FRAPS. Looking at the Frame Time chart you can see that when run in a CrossfireX configuration the frame time data is all over the board whereas NVIDIA's multi GPU solution delivers a consistent line across the chart. Slightly wider than the single GPU line but still much improved over the AMD configurations. Another look using the percentile chart illustrates this a little differently, showing that as the outliers are removed the FPS takes a downward swing. The results from one game do not tell the whole tale so looking at BF3 as well as Far Cry 3 provides a pair of results to illustrate the point with a little larger base of video cards.
Another look is created in the Run.Stat charts that show the difference between what is reported in the FCAT tools and what is counted by FRAPS. Looking at the NVIDIA solution first shows the blue and black lines match up fairly consistently with no runt or dropped frames evident due to how NVIDIA manages the frame rates. AMD, on the other hand, shows the effects of the frame time issues on the observed and reported FPS with a large section of dropped and runt frames evident that correspond to choppy game play. It's mostly a graphic representation of the problem that has been a concern for some time. Each game will show a different result based on how well the engine is optimized for a particular graphics solution. The Far Cry 3 results are telling on their own but moving to BF3 you can see some wild swings in the charts. Again mimicking the game experience.
Trolling through the data can be pretty daunting initially as there is just so much to work through. To put it in perspective and put it in an easier to understand format we can look at the true FPS output seen on the screen versus the average FPS we are used to seeing when using FRAPS. We have two numbers to look at: the Observed FPS, which is the FPS reported by FRAP,S and the New FPS that is reported by the FCAT tools.
As the charts show when you take out the runt and drop frames you get a significantly lower result based on the game tested and GPU combination used. The average FPS reported for the NVIDIA combinations results were almost identical when any runt and/or dropped frames were pulled from the averages whereas the AMD combination took a performance hit due to the wildly varying frame time latencies and FPS delivered. Single GPU results do not suffer this kind of symptom due to the reduction in frame time latency. When you look at the charts it's clear that NVIDIA has been taking the results of this technology and tuning its dual GPU options to get the smoothest game play.