AMD Frame Pacing Explored: Catalyst 13.8 Brings Consistency to Crossfire
by Ryan Smith on August 1, 2013 2:00 PM ESTCatalyst 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.
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.
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.
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.
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boot318 - Thursday, August 1, 2013 - link
I've read a couple people got "black screened" when they did this update on one GPU. I'm not saying that will happen, but you better prepare for it if you do.Bob Todd - Thursday, August 1, 2013 - link
I may have missed this when I skimmed through the results, but have you heard anything about rough estimates from AMD about a frame pacing release supporting Eyefinity (e.g. Q4, H1 2014, etc.)? I know it's still a tiny percentage of users, but there are relatively cheap 1080p IPS panels now so building a nice looking 5760x1080 setup is pretty affordable these days. After playing games this way, it's something I wish I had done earlier, and I'm eager to see a frame pacing driver supporting this setup.Ryan Smith - Thursday, August 1, 2013 - link
Sorry, AMD didn't give us an ETA on that one. Let me see if I can still get one out of them.DanNeely - Thursday, August 1, 2013 - link
HardOCP says DX9 and Eyefinity support should be available in a driver update later this month.http://www.hardocp.com/article/2013/08/01/amd_cata...
DeviousOrange - Thursday, August 1, 2013 - link
I am hoping this will also improve Dual Graphics, will give it a test over the weekend.Homeles - Thursday, August 1, 2013 - link
Well I'll be damned. They did it. Not quite as good as Nvidia, but at this point, the difference isn't really one worth mentioning.xdrol - Thursday, August 1, 2013 - link
The link is bad for the driver, please remove "-auth" from the URL.chizow - Thursday, August 1, 2013 - link
Like watching a baby crawl. Good first step for AMD, but still a long way to go.AMD and their fans can thank the press (mainly TechReport and HardOCP, sorry Derek, you guys were way late to the party and still not fully onboard with FCAT measurements) and Nvidia fans for making such a big stink of this. Lord knows AMD and their fans were too busy looking the other way to address it, anyways.
Hopefully AMD and their fans take something away from this: if you want to improve your product, don't try to sweep it under the rug, address it, own it, and demand a fix for it.
chizow - Thursday, August 1, 2013 - link
Sorry my above post should reference the author Ryan, not Derek (was thinking of your predecessor), when referring to AT not being at the forefront of this runtframe/microstutter issue.Also, I feel the accolades given to TechReport, while not completely undeserving, should also be given to PCPer's Ryan Shrout and some of the German publications like PCGamesHardware. While TechReport did start the ball rolling with some new ways to measure frame latency/microstutter, Ryan Shrout really harped on the runtframe issue until Nvidia worked with him in unveiling FCAT. Also, the German sites have been hammering AMD for years about their much worst microstuttering in CF, largely ignored by the NA press/blogs. And finally Kyle at HardOCP has said for years SLI felt smoother than CF with some Pepsi challenge type user testing, but not so much hard evidence as presented here as well as other sites.
Finally Ryan, are these new metrics you've done an excellent job of formulating going to make it into future benchmarks? Or are you going to just assume the issue has been fixed going forward? I would love to take AMD's word on it but as we've seen from both vendors in the past, driver regression is commonplace unless constantly revisited by users, reviewers, and the vendors alike.
Ryan Smith - Friday, August 2, 2013 - link
"Finally Ryan, are these new metrics you've done an excellent job of formulating going to make it into future benchmarks?"They'll be in future articles in a limited form, similar to how we handled the GTX 780 launch. It takes a lot of additional work to put this data together, which isn't always time we have available. Especially if it becomes doing hours of extra work to collect data just to say "yep, still no stuttering."