Ashes of the Singularity Revisited: A Beta Look at DirectX 12 & Asynchronous Shading
by Daniel Williams & Ryan Smith on February 24, 2016 1:00 PM ESTDirectX 12 vs. DirectX 11
Now that we’ve had the chance to look at DirecX 12 performance, let’s take a look at things with DirectX 11 thrown into the mix. As a reminder, while the two rendering paths are graphically identical, the DirectX 12 path introduces the latter’s multi-core scalability along with asynchronous shading functionality. The game and the underlying Nitrous engine is designed to take advantage of both, but particularly the multi-core functionality as the game pushes some very high batch counts.
Given that we had never benchmarked Ashes under DirectX 11 before, what we had been expecting was a significant performance regression when switching to it. Instead what we found was far more surprising.
On the RTG side of matters, there is a large performance gap between DX11 and DX12 at all resolutions, increasing with the overall performance of the video card being tested. Even on the R9 290X and the 7970, using DX12 is a no brainer, as it improves performance by 20% or more.
The big surprise however is with the NVIDIA cards. For the more powerful GTX 980 Ti and GTX 780 Ti, NVIDIA doesn’t gain anything from the DX12 rendering path; in fact they lose a percent or two in performance. This means that they have very good performance under DX11 (particular the GTX 980 Ti), but it’s not doing them any favors under DX12, where as we’ve seen RTG has a rather consistent performance lead. In the past NVIDIA has gone through some pretty extreme lengths to optimize the CPU usage of their DX11 driver, so this may be the payoff from general optimizations, or even a round of Ashes-specific optimizations.
Breaking down the gains on a percentage basis at 1080p, the most CPU-demanding resolution, we find that the Fury X picks up a full 50% from DX12, followed by 29% and 23% for the R9 290X and 7970 respectively. Meanwhile at the opposite end of the spectrum are the GTX 980 Ti and GTX 780 Ti, who lose 1% and 3% respectively.
Finally, right in the middle of all of this is the GTX 680. Given what happens to the architecturally similar GTX 780 Ti, this may be a case of GPU memory limitations (this is the only 2GB NVIDIA card in this set), as there’s otherwise no reason to expect the weakest NVIDIA GPU to benefit the most from DX12.
Overall then this neatly illustrates why RTG in particular has been so gung-ho about DX12, as Ashes’ DX12 path has netted them a very significant increase in performance. To some degree however what this means is a glass half full/half empty full situation; RTG gains so much from DX12 in large part because of their poorer DX11 performance (especially on the faster cards), but on the other hand a “simple” API change has unlocked a great deal of GPU power that wasn’t otherwise being used and vaulted them well into the lead. As for NVIDIA, is it that their cards don’t benefit from DX12, or is it that their DX11 driver stack is that good to begin with? At the end of the day Ashes is just a single game – and a beta game at that – but it will be interesting to see if this is a one-off situation or if it becomes recurring.
Facebook
Twitter
RSS
153 Comments
View All Comments
BurntMyBacon - Thursday, February 25, 2016 - link
@anubis44: "nVidia wasn't expecting AMD to force Microsoft's hand and release DX12 so soon."I do believe you are correct. Given the lack of ability to throw driver optimizations at the DX12 code path and nVidia's proficiency at doing it, I'd say this will be quite damaging. They've lost one clear advantage they held (at least in DX11).
@anubis44: "It's beginning to look like nVidia's been check-mated by AMD here."
I wouldn't go that far. They probably won't have the necessary hardware in Pascal, but you can be sure Volta will have what it needs. Besides, most games will likely have a DX11 code path for the foreseeable future as developers wouldn't want to lock themselves out of an entire market. Also, at the moment, nVidia can still play DX12 fine, they just don't appear to have the advantage at the moment given the small sample set of available data points.
In conclusion, it is more like they have lost a rook or queen. Of course, they've taken a few of ATi's pieces as well, so lets just wait and see who plays their remaining pieces better.
rhysiam - Thursday, February 25, 2016 - link
The other thing I would add to this is that it's not like Nvidia have nowhere to go here. Take the GTX 970 vs the R9 390 for example... they're in a similar price & performance tier. Yet the 970 is smaller with fewer transistors (usually meaning it's cheaper to produce) and generally has a much higher overclocking headroom (because Nvidia wasn't under pressure to clock the card closer to the limit to reach relevant performance). So it's reasonable to expect Nvidia could both lower the price and clock it higher to get a significantly better value card with minimal basically no substantive engineering/architectural changes.I'm not suggesting Nvidia will do that with the 970 specifically. Rather, what I'm saying is that if they find Pascal is similarly behind AMD they've got plenty of room to tweak performance and price before we can start calling them "check-mated". But it's certainly good new for us if DX12 performance like this continues and AMD essentially forces Nvidia to lower its margin.
CiccioB - Sunday, February 28, 2016 - link
They can do exactly as AMD has done with GCN: they just can start using 30 or 50% bigger GPUs to close the performance gap if they really need to.The_Countess - Thursday, February 25, 2016 - link
nvidia's entire performance advantage in DX11 is based on game specific driver optimizations. they have a virtual army of developers slaving away on those (and coming up with way to hurt everyone's performance as long as it hurt AMD the most or makes their own latest gen cards look better... but that's a different matter)with DX12 however the drivers becomes MUCH thinner and doesn't have nearly as much influence. so basically nvidia's main competitive advantage is gone with dx12 and vulkan.
as for being relevant: this year pretty much every game where performance matters will have either a DX12 or Vulkan render option. adding in the fact that AMD cards generally age better then nvidia's (those game specific optimizations focus pretty much exclusively only on their latest generation of cards) and i would say that yes it is very relevant.
BurntMyBacon - Thursday, February 25, 2016 - link
@The_Countess: "nvidia's entire performance advantage in DX11 is based on game specific driver optimizations. they have a virtual army of developers slaving away on those ..."True, they have lost a large advantage. Keep in mind, though, that nVidia's developer relations are still in play. What they once achieved through the use of driver optimizations may still be accomplished through code path optimization and design guidance for nVidia architecture. The first beta for Vulkan (The Talos Principle) showed that merely replacing a high level API (OpenGL/DX11) with a low level one (Vulkan/DX12) does not automatically improve the experience. If nVidia can convince developers to avoid certain non-optimal features or program in such a way as to take better advantage of nVidia hardware in their titles (for the sake of performance on the majority of discrete card owners out there of course) then ATi will be in the same position as they are now. Better hardware, worse software support. Then again, low level API cross-platform titles will most assuredly program to take advantage of the console architectures which happens to be ATi's at the moment.
nevcairiel - Wednesday, February 24, 2016 - link
Considering the Fury X just has a tad bit more raw power than a (older) 980Ti, I would say the DX12 numbers are fine, and what is really showing is AMDs lack of performance in DX11?tuxRoller - Wednesday, February 24, 2016 - link
I don't agree with this. I think this is more a case of nvidia not being able to rely so much on the ENORMOUS number of special cases in their driver.IOW, this is about two things: hardware and game design. The drivers are trivial next to d3d11/ogl.
jasonelmore - Wednesday, February 24, 2016 - link
Fury X's Architecture is much newer than Maxwell 2's. Lets see what the true DX12 cards can do this summer.tuxRoller - Wednesday, February 24, 2016 - link
Did you not notice the across the board improvements for all gcn cards?The point I was making, and that others have made for sometime, is that AMD makes really good hardware but this is typically masked by poor drivers.
You can see this by looking at their excellent performance in compute workloads where the code in the driver is more recent and doesn't have the legacy cruft of their d3d/ogl code.
Despoiler - Thursday, February 25, 2016 - link
It's not their drivers. It's purely architectural. GCN moved their schedulers into to hardware. GCN requires the API to be able to feed it enough work. What people have been calling "driver overhead" is nothing of the sort. DX11 is just not capable of fully utilizing AMD hardware. DX12 is and that is why AMD created Mantle. It forced MS to create DX12 and that set off the creation of Vulkan. All of the next gen APIs are tailored to exploit AMDs already being sold hardware.