Final Words

Bringing things to a close, today’s driver release isn’t about any grand revelations for AMD, but rather about AMD following through on their plans and commitments to improve frame time consistency on their products. We’ve seen AMD get their house in order with respect to single-GPU cards earlier this year, and now the same is starting to happen for multi-GPU setups.

To be clear here AMD’s initial situation should never have happened. AMD should have been doing the appropriate competitive analysis from the start, never letting themselves fall behind like this. But we aren’t in the business of berating companies that make an honest effort to improve their products like AMD is doing, so while AMD could have done better in the past they are finally making the right moves in the present, and it’s the present that’s going to be the most important for AMD’s customers.

So what does AMD’s present look like? Quite frankly, it looks a lot better than it did yesterday. AMD set out to greatly improve on their frame pacing situation on their Crossfire setups and they have delivered just that. With just one driver revision we have seen the Radeon HD 7990’s frame pacing go from laughable to acceptable; delta percentages of over 100% have been reduced to 20% or lower in 5 of the 6 games we’ve tested. For those sensitive to micro-stutter and other matters of consistency the difference is at times going to be staggering. At the most basic level, AMD has achieved their objectives.

With that said, there’s still room for improvement, and this goes for both functionality and further improvements in frame consistency. AMD’s triage-like approach means that D3D9, OpenGL, and most importantly Eyefinity are still not capable of using frame metering. These will be covered in future phases of AMD’s rollout of their frame pacing technology, and they can’t come soon enough, but for the time being these are limitations that need to be kept in mind.

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

Similarly while AMD’s frame pacing has improved to the point where we find it acceptable, 20% deltas are still generally twice that of NVIDIA’s GeForce GTX 690, never mind the extreme consistency single-GPU setups offer. We never realistically expected AMD to match NVIDIA’s frame interval consistency overnight, but in time it would be nice to see them get close, and for both parties to further improve beyond that.

Moving on, while today’s driver release is primarily one part of AMD’s longer term plan to deal with frame interval consistency, AMD is trying hard to also use this moment as something of a second launch for the Radeon HD 7990. With the 7990 launching in April it had the poor timing of arriving shortly after the multi-GPU frame pacing issue came to a head, which is something that has hobbled the card since its launch. In terms of absolute performance (average frame rates) things have changed very little since the launch of the 7990 so we’re not going to get into the matter of performance.

What has changed since then for the 7990 is first and foremost its frame pacing improvements as we’ve seen today. To be very clear here the GTX 690 is still the better card for those users heavily concerned about consistency, but AMD’s improvements have brought the 7990 to the point where we find its frame consistency generally acceptable. This isn’t a rousing recommendation nor is it meant to be, but it’s a reflection of the fact that AMD has brought their consistency to the point where pairing up multiple Tahiti GPUs as is done in the 7990 is no longer fraught with the frame pacing problems it once was. For most users I believe we’re to the point where the consistency differences are greater on paper than they are on the eyes, but of course that is going to depend on the visual acuity of the user.

Moving on, the other thing that has changed for AMD is pricing and competitive positioning. Officially AMD hasn’t cut the price on the 7990, but the fact that XFX is now offering a reference 7990 for $799 after rebate is not a coincidence. With AMD’s Level Up with Never Settle Reloaded promotion still running, AMD is making a clear play for the value segment right now. I don’t believe it’s where AMD would like to be, but there’s no arguing that it’s effective. 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.

With that in mind, we do want to reiterate that our editorial position here on AFR setups isn’t changing. We still favor strong single-GPU setups over weaker multi-GPU setups, but this is a matter of valuing the lack of AFR profile requirements, coupled with the tendency for newly launched games to have immature AFR profiling, and of course the general consistency issues we’ve covered today. AFR is still the only way to further improve performance once the single-GPU route has been exhausted, and in AMD’s case it’s the only way to exceed the performance of a 7970 GHz Edition, so it does have its place.

Ultimately we have to give AMD the kudos they deserve. They have come forward about their issues, set out a plan to fix them, and have begun delivering on those plans. There’s still room for further improvement within AMD’s drivers, so AMD’s job is far from done, but today they have taken the first step needed to settle the frame pacing problems that have been dogging their products.

Crysis 3
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  • chizow - Friday, August 02, 2013 - link

    That makes sense, but I guess the bigger concern from the outset was how AMD's allowance of runtframes/microstutter in an "all out performance" mentality might have overstated their performance. You found in your review that AMD performance typically dropped 5-10% as a result of this fix, that should certainly be considered, especially if AMD isn't doing a good job of making sure they implement this frame time fix across all their drivers, games, APIs etc.

    Also, any word whether this is a driver-level fix or an game-specific profile optimization (like CF, SLI, AA profiles)?
    Reply
  • Ryan Smith - Friday, August 02, 2013 - link

    The performance aspect is a bit weird. To be honest I'm not sure why performance was up with Cat 13.6 in the first place. For a mature platform like Tahiti it's unusual.

    As for the fix, AMD has always presented it as being a driver level fix. Now there are still individual game-level optimizations - AMD is currently trying to do something about Far Cry 3's generally terrible consistency, for example (an act I'm convinced is equivalent to parting the Red Sea) - but the basic frame pacing mechanism is universal.
    Reply
  • Thanny - Thursday, August 01, 2013 - link

    Perhaps this will be the end of the ludicrous "runt" frame concept.

    All frames with vsync disabled are runts, since they are never completely displayed. With a sufficiently fast graphics card and/or sufficiently less complex game, every frame will be a runt even by the arbitrary definitions you find at sites like this.

    And all the while, nothing at all is ever said about the most hideous artifact of all - screen tearing.
    Reply
  • Asik - Thursday, August 01, 2013 - link

    There is a simple and definite fix for tearing artifacts and you mention it yourself - vsync. If screen tearing bothers you, and I think it should bother most people, you should keep vsync on at all times. Reply
  • chizow - Thursday, August 01, 2013 - link

    Vsync or frame limiters are certainly workarounds, but it also introduces input lag and largely negates the benefit of having multiple powerful GPUs to begin with. A 120Hz monitor would increase the headroom for Vsync, but also by nature reduces the need for Vsync (there's much less tearing). Reply
  • krutou - Friday, August 02, 2013 - link

    Triple buffering solves tearing without introducing significant input lag. VSync is essentially triple buffering + frame limiter + timing funny business.

    I have a feeling that Nvidia's implementation of VSync might actually not have input lag due to their frame metering technology.

    Relevant: http://www.anandtech.com/show/2794/3
    Reply
  • chizow - Saturday, August 03, 2013 - link

    Yes this is certainly true, when I was on 60Hz I would always enable Triple Buffering when available, however, TB isn't the norm and few games implemented it natively. Even fewer implemented it correctly, most use a 3 frame render ahead queue, similar to the Nvidia driver forcing it which is essentially a driver hack for DX.

    Having said all that, TB does still have some input lag even at 120Hz even with Nvidia Vsync compared to 120Hz without Vsync (my preferred method of gaming now when not using 3D).
    Reply
  • vegemeister - Monday, August 05, 2013 - link

    The amount of tearing is independent the refresh rate of your monitor. If you have vsync off, every frame rendered creates a tear line. If you are drawing frames at 80Hz without vsync, you are going to see a tear every 1/80 of a second no matter what the refresh rate of your screen is. The only difference is that a 60Hz screen would occasionally have two tear lines on screen at once. Reply
  • chizow - Thursday, August 01, 2013 - link

    Sorry, not even remotely close to true. Runt frames were literally tiny shreds of frames followed by full frames, unlike normal screen tearing with Vsync off that results in 1/3 or more of the frame being updated at a time, consistently.

    The difference is, one method does provide the impression of fluidity and change from one frame to the next (with palpable tearing) whereas runt frames are literally worthless unless you think 3-4 rows worth of image followed by full images provides any meaningful sense of motion.

    I do love the term "runt frame" though, an anachronism in the tech world born of AMD's ineptitude with regard to CrossFire. I for one will miss it.
    Reply
  • Thanny - Thursday, August 01, 2013 - link

    You're not making sense. All frames with vsync off are partial. The frame buffer is replaced in the middle of screen updates, so no rendered frame is ever displayed completely.

    A sense of motion is achieved by displaying different frames in a time sequence. It has nothing to do with showing parts of different frames in the same screen refresh.

    And vsync adds a maximum latency of the inverse of the screen refresh (16.67ms for a 60Hz display). On average, it will be half that. If you have a very laggy monitor (Overdrive-TN, PVA, or MVA panel types), that tiny bump from vsync might push the display lag to noticeability. For plain TN and IPS panels (not to mention CRT), there will be no detectable display lag with vsync on.
    Reply

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