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Catalyst 13.8 Results in Summary

For this article we’ve decided to do things a bit differently and lead in with a summary of our results, rather than starting with detailed results and then going to a summary. Based on past feedback most of you want to quickly know whether this works at all and how well it works, which is something we can quickly cover first before diving into individual games.

We’ll start with the graph that is of the most importance: delta percentages on a 7990, comparing Catalyst 13.6b2 to Catalyst 13.8b1 with frame pacing enabled.

AMD Radeon HD 7990 Delta Percentages: Cat 13.6 vs. Cat 13.8

The results, quite frankly, speak for themselves. In roughly half of our 6 games AMD had absolutely absurd frame pacing on Catalyst 13.6. Total War, Sleeping Dogs, and Battlefield 3 all had massive pacing issues that were the result of second frames coming far too soon after first frames, leading to a high instance of “runt” frames – that is frames that are only shown for an incredibly short period of time before being replaced with a newer frame. These are the games where micro-stuttering and/or the feeling of lower frame rates would be the most apparent.

Earlier we decided that our cutoff would be 15%-20% for an “acceptable” range for delta percentages on a multi-GPU setup, and with the exception of Total War: Shogun 2 (the only non-action game in this collection), AMD has just managed to hit that. How smooth this is going to be perceived is going to vary on a person-by-person basis, but this is right where we’d say micro-stuttering and other issues become generally unnoticeable.

For the more visually inclined, we’ve also quickly cooked up frame time graphs in FCAT showing the two 7990s. The full series is below, but we’ll print in full the Total War: Shogun 2 graph in full since it was one of the bigger problem cases for AMD’s cards without frame pacing. Shogun doesn’t have any scene transitions, but it does have some snap camera movements that leads to a clear separation between scenes. In each scene we can clearly see the much lower variability with Catalyst 13.8 with frame pacing turned on, as opposed to 13.6 with frame pacing turned off.

Similarly, turning off frame pacing results results in Catalyst 13.6-like behavior, with much higher variability compared to having frame pacing turned on.

Moving on, the next question on most readers’ minds will probably be performance. What’s the performance sacrifice for using this new frame pacing mechanism? AMD said that the performance hit should be non-existent, and strictly speaking within Catalyst 13.8 that’s true, as we get identical frame rates with it on or off. However compared to Catalyst 13.6 we are seeing a performance regression.

AMD Radeon HD 7990 Framerates: Cat 13.5, Cat 13.6, & Cat 13.8

With the exception of Hitman: Absolution, performance is down across the board on 13.8 versus 13.6. The specific performance losses vary on the game, but we’re looking at 5-10%. However compared to the 13.5 launch drivers and again with the exception of Hitman AMD’s performance has held constant or increased. So at the very least when it comes to frame rates AMD is no worse off than they were at the launch of the 7990.

Our next summary graph is plotting the 7970GE against a pair of 7970GEs in Crossfire, to take a fresh look at AFR (Crossfire) versus a single GPU. Our editorial position has been and remains that we favor a single larger GPU over a pair of smaller GPUs when this approach is practical, and this chart demonstrates exactly why.

AMD Radeon HD 7970GE Delta Percentages: One vs. Two GPUs

The delta percentages on the single 7970GE are all under 2%, versus 12%+ for the Crossfire setup. AFR simply cannot match the consistency of a single GPU at this time, which is why a high AFR is best left to being pursued after single-GPU performance has been exhausted.

The Test Catalyst 13.8 Results in Summary, Cont
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  • bl4C - Sunday, September 15, 2013 - link

    Hello Ryan,
    It would be interesting to see what this new FCAT testing system can learn us about the Lucid Virtue technology:
    I don't think I've seen any conclusive benchmarking yet, because traditional frame rates reported are not "real" when using Lucid Virtue ... Any idea if FCAT can learn us something meaningful, any change you could shed some light on it ?
    Reply
  • DerekPDX - Friday, October 04, 2013 - link

    Does this address the frame pacing issue with dual graphics and Richland APUs? Reply

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