RTX Features – Ray Tracing and DLSS
One of the more confusing parts of the Turing announcement to consumers has been the idea of "RTX" and exactly what it means. Considering "RTX" is the namesake of these new GPUs, it's essential to understand precisely what is being marketed here.
RTX is essentially the term for any graphics technologies implemented using either the Tensor core or RT core capability (or any combination thereof) of Turing. In this initial release, that means either real-time ray tracing (using RT Cores), or DLSS (using the Tensor cores).
Ray Tracing
We've already talked about the underlying technology behind Real-time ray tracing on Turing GPUs, the RT Cores which enable hardware acceleration of BVH transversal, but as with everything, ray tracing will require more than just hardware support.
Announced earlier this year at the Games Developer Conference, Mircosoft's DirectX Ray Tracing (DXR) APIs are an attempt to provide software support for developers implementing ray tracing in games.
While DXR is hardware agnostic and even features a fallback layer for rendering on devices without any specific hardware ray tracing support, NVIDIA's RT cores are currently the only hardware that will accelerate DXR.
To initially demonstrate RTX, NVIDIA worked with ILMxLAB to produce the Star Wars: Reflections demo. Powered by 4 Tesla V100 GPUs, Reflections was the first example of a ray traced, "movie quality" scene running in real-time.
Fast forward to the RTX 2080 and 2080Ti announcement last month, and NVIDIA is now claiming that the addition of RT cores means that they can render this same demo in real-time on a single RTX GPU, bringing real-time ray tracing into the hands of consumers.
As such, NVIDIA also demoed some upcoming PC titles with support for RTX ray tracing, with the biggest being Shadow of the Tomb Raider and Battlefield V.
While overall these ray tracing effects are compelling in demos, it remains to be seen whether or not consumers will care enough about what they offer to purchase new hardware. I had an opportunity to play the RTX version of Battlefield V at the RTX launch event, and it indeed was impressive. Several times during the match, I stopped to marvel at the accurate reflections seen in windows and puddles in the road.
However, since then, the Battlefield V Open Beta has come and pass, and I've had the opportunity to play the same Rotterdam map that was demoed with RTX, but this time with only traditional rasterization. I could indeed tell that I was missing the same fidelity as the RTX demo, but it's going to be an uphill battle to convince gamers to care.
That being said, accurately modeled reflections could be a competitive advantage in a first-person shooter, but that seems like an unlikely scenario to get someone to buy into the RTX family.
While from a technological perspective, Ray Tracing is the holy grail of rendering technology, it may at least initially be difficult to convince developers to put the development into implementing it, given that NVIDIA is currently working from a 0% install rate of RT core hardware in GPUs.
Given that DXR will first be included in the upcoming Windows 10 October Update (RS5), and that games like Shadow of the Tomb Raider and Battlefield V will require patches to enable RTX technology, it remains a question as to when we will actually be able to get our hands-on and test the RT cores of Turing.
DLSS
While NVIDIA has been priming gamers to get ready for Ray Tracing and their RTX API through several announcements over 2018, the more surprising part of the technology suite that NVIDIA is referring to as RTX is DLSS.
Using the Tensor cores found in Turing for its inference capabilities, DLSS is a technology that aims to apply deep learning techniques to accelerate and increase the quality of post-processed anti-aliasing.
To implement DLSS, NVIDIA takes an early build of the given game (which they generally receive anyway for driver optimization) and generates a series of "ground truth" images rendered through 64x Super Sampling.
These extremely high-resolution images are then used to train a neural network which is capable of producing output images that NVIDIA claims are equivalent nearly identical to the original 64x Super-Sampled source material.
In this current stage, the neural network model needs to be trained for each specific game title. In the future, NVIDIA might be able to come up with more generic models that can be applied to particular genres of games, or different game engines, but at this point, it requires hand-tuning from NVIDIA.
Regardless, NVIDIA claims that implementing DLSS will cost game developers nothing and that they are committed to scaling their workflow and supercomputers used for training as far as necessary to meet demand.
This neural network model is then distributed via GeForce Experience to end users who have a GPU with tensor cores and have the given game installed. This distribution model is vital as it allows NVIDIA to silently update the model in the background as they come up with improvements as they get more experience and come up with better techniques.
Performance wise, NVIDIA is comparing the performance hit of enabling DLSS to their most recent push of anti-aliasing technology, TAA. While TAA is already a reasonably lightweight method, NVIDIA is claiming performance benefits of 2X when comparing DLSS to TAA. Also, DLSS is temporally stable, unlike TAA which can help prevent some fast moving details becoming blurred on screen.
While DLSS as a whole seems like a worthwhile initiative, with claims of 64x SSAA quality with very little of a performance hit, the more controversial part is NVIDIA pushing DLSS as a significant performance differentiator from previous GPUs.
A lot of the early performance claims that NVIDIA has been making about these Turing GPUs go out of their way to also show DLSS as part of the performance increase story of Turing over Pascal.
Even if these performance numbers are indicative of the advantages that DLSS can give over traditional AA techniques, you have to place a lot of faith in this feature being implemented in the games you want to play to take this into account vis-a-vie a purchasing decision.
NVIDIA's RTX technologies certainly seem to be pushing the game forward as far as technological potential for PC gaming is concerned. However, for a company that has been much maligned for other, similar developer targeted initiatives like GameWorks, it will be a thin line to straddle between their claims and actual implementation in PC games. This support will be especially important in an era where the consoles drive a lot of the technological direction in games.
Please focus your 2080 review
Please focus your 2080 review on the comparison between it and the 1080ti not the 1080, as the 2070 is more than likely the true replacement for the 1080. Additionally please include 4k none hdr results in your comparison. I have my 1080ti running at 2,139/12,000 under water and am very curious to see the 2080 can match my card in conventional games 4k none hdr, looking forward to your results.
There’s only one metric by
There’s only one metric by which the 20-series should be compared to the 10-series: PRICE.
Also, this deep-learning AA stuff should be DISABLED for raw benchmarking. If NVIDIA wants to sell us on RTX, they can’t pretend that we only play 7 games they have released profiles for.
Cherry-picked BS won’t be tolerated. Don’t pull a Tom’s Hardware “just buy it” move.
Look a dumb@$$ AMD fanboy
Look a dumb@$$ AMD fanboy trying to dictate the terms of a review.
If DLSS is AA and not upscaling it should be turned on and compared to AMD running comparable Quality AA. Sorry if the numbers will look bad for VEga.
so, where exactly did the
so, where exactly did the other guy mention or even imply AMD fanboyism?
Calling out a company for BS tactics is exactly just that: calling out a company for BS tactics.
Considering I only have
Considering I only have Intel/NVIDIA setups in my house, I’m hardly an AMD fanboy. BS is BS, no matter who’s selling it. Raw performance for the dollar is the only real factor that matters. NVIDIA is pushing ray tracing (very little support) and upscaling tricks (also minimal support) in order to distract from the fact that they are offering – at best – 30% more performance for 80% more money. Like I said, BS.
Agree. The GTX 2080 is ~20 %
Agree. The GTX 2080 is ~20 % more expensive for providing only ~5 % of performance bump compared to the GTX 1080 Ti.
I suspect nVidia’s goal is to make the GTX 1080 Ti look cheap while it’s not.
The World Health Organization is right, video game is an addiction like tobacco, casinos, etc
If only price should be
If only price should be compared, go get a free GPU from a trash recycler. Because it’s free, the price is zero, and the price/perf is for all intents and purposes, infinite. Price, performance, and price/performance all matter.
Test all of the new stuff but it’s probably not a good idea to buy based on future technologies. AMD users who counted on DX12 giving them a big jump later a la FineWine learned this the hard way, and now Nvidia users should learn from that and not make the same mistake.
Conversely it’s idiotic to dismiss DLSS/Ray Tracing when the reviews aren’t even out yet.
I would hope that any
I would hope that any competent reviewer would run benchmarks for both support and unsupported games. And then show the benchmarks for supported games with it on and off.
Nice overview of the
Nice overview of the internals, but how about some actual simple benchmark comparisons with previous gen cards?
Don’t you think Ken would
Don’t you think Ken would have included a performance evaluation if he could? They’re under embargo and were only allowed to talk about the architecture. If you check out the other major websites it’s the same situation everywhere.
What everyone is waiting for,
What everyone is waiting for, to see where they end up for example here:
https://www.videocardbenchmark.net/high_end_gpus.html
Are the AIB vendors going to
Are the AIB vendors going to lock down the Nvidia OC scanner feature to only their own cards? At launch Precision X’s scanner worked with my 1080FE only to have later versions say that my card was not supported as it was not “EVGA”.
Did the MSI tool have this restriction?
The previous Precision X
The previous Precision X Scanner was a feature that EVGA implemented and only worked with EVGA cards as you noticed.
NVIDIA Scanner will work with all GPUs, no matter the vendor and can be implemented into any of the NVAPI applications like Afterburner, and software from ASUS, Gigabyte, etc.
“The NVLink interface now
“The NVLink interface now handles Multi-GPU (SLI)”
I would not call NVLink “SLI” any more than I would call AMD’s Infinity Fabric/xGMI “CF” as there is more to NVLink than just some SLI type driver only managed Milti-GPU. NVLink has more hardware based cache coherency protocol communication capabilities for Nvidia’s GPUs(Power9’s to Nvidia GPUs also) and that’s also true for AMD’s Infinity Fabric/xGMI interface, and that xGMI is supported on both Zen and Vega. There is on both NVLink and Infinity Fabric a more direct processor(CPU to GPU and GPU to GPU) cache to cache coherency siginaling capabilities than any SLI/CF driver managed multi-GPU could ever hope to achieve.
I think that both NVLink and Infinity Fabric will allow multiple physical GPUs to appear more like a single larger logical GPU to drivers and software. And this IP has the potential for future modular die based offerings that Both AMD and Nvidia are researching for muiti-die module based GPUs on future products.
Also in both the DX12/Vulkan API’s driver model the GPU’s drivers are simplified and to the metal with any Multi-GPU load balancing given over to the games/gaming engine developers and SLI/CF are depreciated IP that are not going to be used for DX12/Vulkan gaming. Both DX12/Vulkan has that Explicit Mulit-GPU Adaptor IP in their respective APIs that’s managed via these graphics APIs and the game/gaming engine software that makes use of the DX12/Vulkan.
You are also missing the Integer performance(INT32) on that chart where you only list the FP32 performance. It looks like Nvidia may have begun to release more whitepapers and there is probably some patent filings to go over to get some Idea of just what Nvidia has implemented in its RT core hardware. That Tensor Core AI based Denoising needs a deep dive also and I think that Nvidia does the AI algorithm traning on its massive Volta Clusters and then loads that trained AI onto the AI cores on Turing so that process needs a deep dive as well.
I’d expect a continous refinement for the Denoising AI over time in addition to the DLSS AI based Anti Aliasing/other algorithm training. Tensor Cores AI based sound processing and even compression, physics/other AIs are also possible once there are hardware based tensor cores to help speed up the process over any more software based AI solutions.
Also for refrence is Jeffrey A. Mahovsky’s Thesis Paper(1) on Reduced Precision Bounding View Hierarchy (BVH). He is often quoted in many other’s newer papers on the subject.
(1)
”
THE UNIVERSITY OF CALGARY
Ray Tracing with Reduced-Precision Bounding Volume Hierarchies
by
Jeffrey A. Mahovsky”
https://pages.cpsc.ucalgary.ca/~brosz/theses/PhD%20Thesis%20-%202005%20-%20Jeffrey%20Mahovsky%20-%20Ray%20Tracing%20with%20Reduced-Precision%20Bounding%20Volume%20Hierarchies.pdf
How about a direct link to
How about a direct link to the Nvidia whitepaper if possible as there is a lot of material to be covered.
Techreport’s article has explaned BVH in a ELI5 manner in their writeup but they do have a copy of the Nvidia whitepaper so if Nvidia has published it on their website a link to the whitepaper would be helpful.
and here it is(1):
(1)
“NVIDIA TURING GPU
ARCHITECTURE
Graphics Reinvented”<--* *-->[see that phrase that’s marketing’s dirty hands right there, but still the whitepaper is very informative as Nvidia’s whitepapers usually are]
https://www.nvidia.com/content/dam/en-zz/Solutions/design-visualization/technologies/turing-architecture/NVIDIA-Turing-Architecture-Whitepaper.pdf
Anyone has any idea (or
Anyone has any idea (or educated guess) if it will be possible to use RayTracing and DLSS at the same time? I mean, they both use tensor cores so would they be competeing for resources? Will there be enough tensor cores to do both?
Raytracing uses RTX cores.
Raytracing uses RTX cores. It only uses the Tensor cores for Denoising which happens at a different “stage”. Nvidia put out a chart showing when each core is active. But the answer is yes.
There is a link to the Nvidia
There is a link to the Nvidia Turing whitepaper right above and why do you not go and read that and then ask questions. That’s where all the Online Tech “Journalists” got their material for their articles on Turing.
If you want some better explanations go over to TechPowerUp’s and the TechReport’s articles on Turing as they are doing a better ELI5 treatments. Don’t bother with Anandtech’s article as you will spend more time swatting at the annoying auto-play ads than you will spend trying to read!
And teach your children to go over to the local College Library and read the Proper Academic and Professional Trade Journals that are usually paywalled online. Most colleges with computer science departments have the proper subscriptions paid to the online Academic and Professional Trade journals that can be accessed via the college library’s web address if you use the library’s available PCs/terminals or maybe even wifi. LexusNexus is a million times better than Google.
P.S. some College Libraries are Student Only but if the College Library is an official Goverment Document Depository Library/Federal Depository Library Program (FDLP) member then that library has to be open to the public by law. The local State University/Junior College libraries are the most open but in large Metropolitan Areas(The Northeast mostly) the homeless have ruined the public access to many private Universities’ Libraries!
But Ray Tracing is done on Turing’s RT cores and the AI is done via the Trained AI running on the Turing Tensor Cores so that implies some possible concurent Ray Tracing(On the RT cores) and Denoising on the Tensor cores as they are different sets of functional blocks on the GPU. The Tensor cores can be used for all sorts of AI based processing including that DLAA and even audio processing can be done on Tensor Cores. Tensor Cores are just Hardware Based matrix math units anyways!
One of the best College electives that I have ever had was a 1-credit hour per semester Library Science Class. That curriculum was offered over a few semesters with different Library Science research and categorization methods learned with each diffferent 1-credit Hour/Semester LS101/LS102 curriculum and that made my research process so much more productive.
Right. No college for my
Right. No college for my kids, don’t live in US or any other country that has college for that mater.
About Ray Tracing – I was thinking that since it uses tensor cores for AI acceleration and DLSS is using it to decode and apply hints for upscaling content (it was stated that the DLSS is running purely on tensor cores and that cuda cores send completed picture to tensor cores to be “upgraded” and then back for further processing down the pipeline). We are all reading about how compute demanding RT is and tensor cores are used for (I think, correct me if I’m wrong here) ray collision detection (or is that one done in RT cores?) and again for AI accelerated denoising – I supposed that tensor cores would be Very Busy with work and may not like the contention for resources. Unless DLSS is actually very light on workload or somehow they are working at different times? (wonder how would that work with consecutive frames going through pipeline).
Several questions for your
Several questions for your review:
RTX – is raytracing performance independent of resolution? I can’t understand why the number of rays traced would change due to resolution.. seems like it should be based on number of lights and number of objects.
Is RTX just on/off or will we have 3 or 4 major features you can toggle? Will there be low, medium, high settings?
DLSS – many people are claiming the speedup comes from rendering at a lower resolution and upscaling. If this is the case PLEASE make sure to compare TRUE 1080p to TRUE 1080p and TRUE 4k to TRUE 4k. Don’t fall for marketing BS. HOWEVER, IF this really is just a superior form of AA with no overhead cost please make sure to say that LOUDLY to shut up all the haters.
Raytracing is done for every
Raytracing is done for every pixel on the screen so it is very dependent on resolution. From every light source a ray is traced to every pixel unless it is directional light then only the subset of pixels affected by the light source is directly traced for.
Then there are all reflections from the pixels that are lighted up by the light source – the complexity rises dramatically.
RTX will have options, quality of shadows, light, reflections and so on based on how many rays are traced and then extrapolated, but there is a lowest limit to how many rays are actually traced because if not enough is traced, the AI thet extrapolates them will fail.
DLSS – as far as Nvidia explained it, it is rendered at target resolution and then AI is used to apply the precalculated cues for textures and objects of how should they look in the “perfect world”. So 4k with TAA should be compared with 4k with DLSS – just as Nvidia is doing on their’s slides.
People clearly don’t
People clearly don’t understand that there is still an NDA in place and all the questions you are asking cannot be answered without severe ramifications until the day everyone and their mother all drops full benchmark articles/videos on the same day like every other release. I’m sure a good portion of those are already made or written and just waiting to go on whatever day the NDA lifts.
This is true and some other
This is true and some other websites have stated that fact and really the FTC should require that all NDA deadlines be published in advance by any device/procesor/whatever makers. This is so consumers can know when the data will be available for the consumer to make an educated purchasing decision!
That Tom’s Hardware USA “Just Buy It” nonsence should have been earning Tom’s hardware USA a big fat fine! But that is the nature of the unregulated online “Press” that’s not held to the same standards as the print and over that air waves TV industries are! Online can be found the same hucksters, grifters, and snake oil salesmen that have been properly regulated out of the Print/TV media by the FCC/FTC for decades.
Most of the “questions” I am
Most of the “questions” I am seeing asked, seem to be more for what they want in the review of the card. Not immediate responses now.