AMD Frame Pacing Explored: Catalyst 13.8 Brings Consistency to Crossfire
by Ryan Smith on August 1, 2013 2:00 PM ESTCatalyst 13.8 Beta 1: The First Multi-GPU Frame Pacing Driver
The culmination of AMD’s first wave of efforts to manage frame pacing is the Catalyst 13.8 driver (driver branch 13.200). Being released in beta form today, the marquee feature for this driver is the new frame pacing mechanism for Crossfire setups. As with any major new driver branch this also includes some other improvements, and while we don’t have the complete release notes, AMD has mentioned that these drivers will bring about full OpenGL 4.3 compliance (apparently they were missing a couple of items before).
AMD is calling this driver “phase 1” of their frame pacing solution, and for good reason. In implementing frame pacing AMD has tackled the issue in what’s very obviously a triage-like manner, focusing on the most important/significant problems and working out from there. So what’s addressed by this first driver resolves AMD’s biggest issues, but not all of them.
So what’s being addressed in phase 1? Phase 1 is being dedicated to Direct3D 10+ games running on a single display. What’s not being addressed in the first driver are the Direct3D 9 and OpenGL rendering paths, along with Eyefinity in any scenario.
It goes without saying that in an ideal would we would have liked to see AMD hit everything at once, but if they couldn’t do it all at once then choosing to tackle D3D10+ games first was the next best move they could make. This covers virtually all of the games present and future that are graphically challenging enough to weigh down a high-end Crossfire setup. D3D9 games by and large are not that demanding on this class of hardware – we’d have to resort to Skyrim mods to find a D3D9-exclusive title that isn’t CPU limited and/or gets less than 90fps off of a single GPU. OpenGL has even less traction, the last OpenGL game of note being 2011’s Rage which is capped at 60fps and easily hits that at 1080p on even 7800 series hardware.
| Catalyst 13.8 Frame Pacing | |||||
| Single Display | Eyefinity | ||||
| D3D11 | Y | N | |||
| D3D10 | Y | N | |||
| D3D9 | N | N | |||
| OpenGL | N | N | |||
It’s Eyefinity users who will be the most unfortunate bunch at the moment. Eyefinity is one of the premiere usage scenarios for Crossfire because of the amount of GPU horsepower required, however it’s also the most complex scenario to tackle – splitting work across multiple GPUs and then multiple display controllers – compared to the fairly low user uptake. More so than with D3D9 and OpenGL AMD does need to get Eyefinity sorted and quickly, but for the moment single display setups are it. On that note, 4K displays are technically also out, since the current 60Hz 4K displays actually present themselves as two displays, with video cards addressing them via Eyefinity and other multi-monitor surround modes.
On the plus side, since this is a purely driver based solution, AMD is rolling out frame pacing to all of their currently supported products, and not just the 7000/8000 series based GCN parts. This means 5000 and 6000 series Crossfire setups, including multi-GPU cards like the 5970 and 6990, are also having their pacing issues resolved in this driver. Given the limited scope of this driver we were afraid it would be GCN-only, so this ended up being a relief.
Moving on, let’s dive into the new driver. True to their word, AMD has made the new frame pacing mechanism a user controllable option available in the Catalyst Control Center. Located in the CrossfireX section of the 3D Application Settings page and simply titled “Frame Pacing,” it defaults to on. Turn it off and AMD’s rendering behavior reverts to the low-lag behavior in previous drivers.
As far as technical details go, AMD has not offered up any significant details on how their new frame pacing mechanism works. Traditionally neither AMD nor NVIDIA have offered a ton of detail into how they implement AFR under the hood, so while unfortunate from an editorial standpoint it’s not unexpected. Hopefully once AMD finishes the other phases and enabling the new frame pacing mechanism elsewhere, we’ll be able to get some solid details on what AMD is doing to implement frame pacing. So for the moment we only have the barest of details: AMD is delaying frames as to prevent any frame from being shown too early, presumably relying on backpressure in the rendering queue to stabilize and keep future frames coming at a reasonable pace.
With that said, based on just the frame time measurements from our benchmark suite we can deduce a bit more about what AMD is doing. Unlike NVIDIA’s “organic” approach, which results in frame times that follow a similar pattern as single-GPU setups but with far wider variation, the frame times we’re seeing on 13.8 have a very distinct, very mechanical metered approach.
Accounting for some slight variation due to how back buffer swapping works, what we see are some very distinct minimum frame time plateaus in our results. Our best guess is that AMD is running some kind of adaptive algorithm which is looking at a window of rendering times and based on that is enforcing a minimum frame time, ultimately adjusting itself every few seconds as necessary. NVIDIA doesn’t implement something quite like this, but beyond that we don’t know how the two compare algorithmically at this time. However regardless of their differences what we’re ultimately interested in is how well each mechanism works.
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anubis44 - Friday, August 2, 2013 - link
TheJian, you seem to be suffering from verbal diarrea. You might want to take some immodium for that.What you could have said in about 1/10th the space is: you harbour an inexplicable hatred for Ryan Smith, because he's ever said anything positive about an AMD product, and that you think that despite AMD's huge stride forward in one driver revision to address and fix a problem with multi-GPU crossfire smoothness (let's face it, a fairly obscure problem, too), nothing AMD will ever do will be good enough for you, because you harbour an inexplicable hatred of AMD, too.
There, I summarized your entire rant in one sentence. Short and sweet. Concision is bliss.
TheJian - Tuesday, August 6, 2013 - link
https://en.wikipedia.org/wiki/Ad_hominemPlease review the chart from Graham, then come back with something at the top of his pyramid instead of the bottom :)
You seem to be suffering from the inability to make a coherent response to a valid argument, thus attack me instead :) It's always amusing to see fanboys flounder when faced with the facts (no matter if I argue for or against a company, it happens on both sides).
I own a radeon 5850...ROFL. I don't care about NV and will state they suck when or if they do. There is a reason I bought the 5850 :) The only thing I hate about AMD is management taking a total dump on one of my favorite companies (probably mostly due to spending all the R&D on consoles, thus screwing my PC choices and driving them directly into the ground). Having said that, I'll buy maxwell next unless something is terribly wrong with it if only for money backing the drivers. You can google my posts here and see I've been begging people to STOP asking AMD for price cuts and free games so they will start making money. I have done this MANY times. I'm not looking forward to NV owning the gpu world and making it too expensive for me to upgrade as much as I please.
No fan of Ryan or Anandtech these days. I'd hope their alexa traffic numbers forces them to start acting like they did pre Sept last year (which are off by half, as people see the points I and others make). People are not being fooled.
transphasic - Tuesday, August 6, 2013 - link
Excellent points, and well said!The AMD fanboy sure is a grumpy one when their feelings get hurt at the fact that their beloved company has DROPPED the ball AGAIN for the hundredth time.
The loudly proclaim to the world that they finally recognize a problem with their CF setup, and have supplied a minor tweak here and there to get a few games fixed, and that we as AMD owners should start cheering loudly for all through the night.
LOL. It has taken them forever to finally see a problem, and then they take forever to fix it after all this time, even when it hasn't been fixed.
AMD reminds of me Kramer from Seinfeld, who tells Jerry that he will give back to him the pliers he borrowed (that he also broke into pieces and destroyed) but only when Jerry does what he wants him to do, and in so doing, makes Jerry feel like he should be happy about it.
Like Kramer, AMD tries in vain to make us very happy about something that should already had been fixed long ago- just like their Enduro nightmare which STILL after 18 months has not be fixed, and when they do come out with a PARTIAL and incomplete fix- as is THEIR obligation after these many years, we are told to feel happy that we at least got SOMETHING.
They took almost 2 1/2 months to come up with a minor fix for some games, and it's still only Beta, and those with single CPU setups got nothing, all the while Nvidia keeps cranking out the WHQLs, and improved Drivers for a wide variety of games- including AMD-based games.
There's a REASON why AMD is so much cheaper, and far less expensive than Nvida GPU's and Intel CPU's, and we all know why- crappy drivers that are slow to come out, poor attention to detail, weak performance across the board on all their product lines, and a lack of motivation about fixing the problems in a timely manner that they chose to ignore in the first place.
As the saying goes, you get what you pay for...
TheJian - Friday, August 2, 2013 - link
"Ultimately we have to give AMD the kudos they deserve. They have come forward about their issues"No we don't have to give kudos to a company with a beta product who hasn't even fully fixed it yet today. It's like shipping cars with 3 tires. Kudos to the company for putting on a 4th tire for the users today...Seriously? NO WAY. And since it doesn't fix everything (XP users see nothing, eyefinity again nothing), it's really just a 4th tire that is FLAT still...ROFL. They didn't come forward either. They were FORCED INTO THE LIGHT. See PCper's comments in my previous post. They told them he was wrong 1/2 dozen times...ROFL. That isn't coming forward, it's denying you have issues.
"For users who have a reasonable level of faith in Crossfire scaling and are satisfied with AMD’s frame pacing improvements, a $799 7990 is a very good deal at the moment."
If you're stupid enough to still believe BEFORE seeing, well you get what you deserve ;) He keeps printing stuff like this. We're not talking Jesus Christ here (whom I guess you need faith in forever right?), this is a company who can't seem to fix problems that have been dogging them for years (not just since april - they've been claiming they had no problem as hardocp shows this is why NV created FCAT to prove AMD wasn't stutter free for years). They still wouldn't discuss the issues with PCper that are ongoing.
"When I asked AMD for more details on WHY Eyefinity wasn't fixed with this release and why it technically was presenting more of a problem, they didn't want to get into it."
Shouldn't they be coming forward with what is going on? Still hiding:
http://www.pcper.com/reviews/Graphics-Cards/Frame-...
" My theory still revolves around the compositing engine that AMD is using for CrossFire and the amount of bandwidth it can handle. Moving a fame of 2560x1600 pixels 60 times a second is taxing but 5760x1080 uses about 50% more pixels is where things seem to break down for AMD."
Of course 4K won't help this situation as he notes later (I pasted that previously). Be careful if you're just reading anandtech people. Read other sites when AMD vs. NV/Intel is the topic being discussed here. You should NOT buy a A8-5600 as Ian suggests in the 1440p articles for single gpu cards, over Intel. It is foolish as I pointed out in the comments on those articles (and I wasn't alone). I can't believe anyone would recommend AMD over Intel for all but extremely poor people. To recommend it for all single gpu people though is just ridiculous (Titan with a $100 cpu? 780, 7970 etc all show Intel running away BELOW 1440p). I listed the games and links to the articles showing this in the 1440p comments sections. GO LOOK then judge anandtech yourself. I'm not sure what they get promoting AMD, and giving them kudos but I hope it's a LOT of $$. Destroying your reputation isn't worth it IMHO.
DeviousOrange - Friday, August 2, 2013 - link
whine, whine, whine, whine, whine, whine, whine.... yeah you are like a broken record.TheJian - Tuesday, August 6, 2013 - link
But always right :) Thanks for verifying it.gi_ty - Friday, August 2, 2013 - link
Whoa there fella, you shouldn't go out on the internet with your stupidity showing like that.TheJian - Tuesday, August 6, 2013 - link
Personal attacks instead of anything about the data. Shocker.https://en.wikipedia.org/wiki/Ad_hominem
Might want to read that and look in the mirror when done. I don't think you made it out of the pink or orange bar in graham's chart ;)
Come back when you can at least crack the top 3. Then we can talk ;) I'm guessing none of you people took debate class (note I didn't just call you stupid, I'm insinuating you're ignorant) :) It's ok to throw in junk from the bottom of the chart (I'd ignore it anyway most likely) but at least give me something to think about. You know, a valid counterpoint backed by something...Otherwise why bother?
Slugbait - Friday, August 2, 2013 - link
Remember back in the day, when the ideal video setup was a Matrox card paired with a couple of Voodoo2 cards? We were all bashing ATi for their drivers back then.Remember when ATi released the Rage, and it didn't come close to the performance that was advertised? (well...Tom's loved it). ATi said it was because they shipped with beta drivers, because their customers really, really, REALLY wanted the hardware NOW. But every subsequent driver release was "beta", and then they cancelled driver development so they could concentrate on a new line called "Radeon". A lot of people here at Anand's (and FiringSquad, Rage3D, AGN3D, etc) were quite peeved.
Remember when you bought any ATi consumer card for your NT Server machine, only to find out that ATi has never written drivers for NT Server, and you had to use Windows generic drivers (no dual-monitor, etc). Want NT Server support? Buy a FireGL or FirePro.
Remember when your CAD program consistently crashed, but everything was perfectly fine after replacing your ATi card with a card from any other company?
"Catalyst" is often used as a dirty word on the forums here.
They have always known that they write poor drivers. This is not some revelation...this is a public spanking by one of their competitors.
Will they finally wake up and turn things around with their drivers? My confidence is...well, it's kinda low.
boozed - Friday, August 2, 2013 - link
If there're two things I've learned from the internet, it's that Nvidia drivers are terrible, and also ATi drivers are terrible.Meanwhile I've had little trouble with either. Am I doing something wrong?