NVIDIA says RTX Is On a lot, but what does that even mean? Ray Tracing is RTX, or is
it DXR? Or is DXR actually RTX? But if that’s the case then how does AMD do it too? NVIDIAs
marketing machine may have gotten those little letters out in front of everyone with big
energy, but when I look around the internet I see quite a few people still confused by
what is and what isn’t RTX. The truth is there’s a lot more to what NVIDIA is referring
to as RTX - quite a bit more actually. In this video, I intend to help you understand
what all the fuss of RTX is about and cover all it encompasses. No, it’s not just ray
tracing.
We’re going to kick off today’s explainer with the very basics to set a foundation of
what RTX is. From a high level RTX is a few things. In fact, just like my previous explainer
where I covered AMD’s FidelityFX, RTX is a very similar story. RTX is the moniker for
an entire set of hardware and software features that NVIDIA has supported since the introduction
of the RTX 20 Series. Basically, if a GPU has the letters RTX in front of it, it supports
these features.
Ray tracing itself is not RTX. You’re likely thinking about ray tracing in Microsoft, DirectX,
or Vulkan. That’s a very important distinction as many still think ALL of ray tracing in
general as ‘RTX’. That’s the result of Nvidia’s heavy marketing and being first
to market with these features.
Part of RTX is Ray Tracing, yes, as that’s the most obvious feature for those who are
even remotely familiar with the terminology. But there are dedicated hardware features
that make a card RTX capable. The RTX umbrella supports features and technologies like Deep
Learning Super Sampling, NVIDIA Studio, and some tech that hasn’t even come to fruition
just yet like RTX I/O.
But what specifically about the hardware side of things that makes a GeForce graphics card
fit the RTX moniker and differentiate itself from previous GTX cards? It’s a simple explanation,
but a GPU basically needs to be able to support all of the RTX functions on a hardware level.
The two most prominent being the ability to support hardware-based ray tracing through
the use of NVIDIAs RT Cores, and the Artificial Acceleration Cores known as Tensor Cores.
First up to bat are the RT Cores and how they handle the Ray Tracing functions within the
GPU Core. When it comes to real-time ray tracing the speed of ray calculations is key. It’s
also extremely difficult, so it needs dedicated silicon for the process. In short order the
RT core handles the calculations that are needed to be done on each light probe in order
to trace that ray for example. Dedicated hardware really was needed to make this possible. It
can be done on traditional shader silicon like we’re used to for years, but this is
all exponentially slower when done on just traditional GPU shaders. That’s why they
suck at it.
But what does ray tracing do for gamers? Well, in short, it adds the ability to have gorgeous,
realistic lighting effects in games. At the extreme you’ve got full path traced games
like Quake 2 RTX or even Minecraft with RTX that no longer render the games using traditional
rasterization. The results are absolutely stunning in accurately lit and displayed worlds.
But that’s extremely taxing even on the most powerful GPUs so games commonly use a
hybrid rendering approach. Hybrid rendered games still mostly use traditionally rasterized
graphics, but add in some ray traced effects, such as ray-traced reflections for accurate
reflective surfaces. There are also accurate shadows, and the most impactful feature in
my opinion. Ray Traced Global Illumination makes games like Metro Exodus Enhanced Edition
really shine.
All that comes at a pretty steep performance cost, however. That’s been considered as
well with the design of the RTX cards.
The other main hardware component is the inclusion of the Tensor Cores that are used for enhancing
matrix operations and used for deep learning and inference operations. This makes them
ideal for workstation applications, research use, and—in the interest of most of our
audience—gaming performance acceleration through the use of Deep Learning Super Sampling,
or DLSS.
Now DLSS has gone through quite a few iterations and continues to be updated so always check
for the latest information on this one. At the time of filming, we’re up to DLSS 2
series. But what is it? DLSS is a pretty unique Anti Aliasing method that utilizes neural
network training to allow games to run at sub native resolution without major loss to
visual clarity. The algorithm takes super-sampled data that it was trained on to reconstruct
the game back to as close to native. In some cases it actually provides better than native
image quality. By simple proxy of rendering the game at a sub native internal resolution
before using tensor cores to upsample, DLSS increases performance.
We recently tested DOOM Eternal as well as Red Dead Redemption 2 to see how the impact
of the latest DLSS implementations shifted performance. When these features are added
into a game we often see what amounts to either a generation or a tier up in performance for
each card. DLSS 2.0 is good stuff.
The biggest drawback to DLSS is that it ONLY works with RTX cards that have the Tensor
Cores on board. So for now it’s certainly a growing market but still has a long way
to go before it’s the norm.
There’s still more to the world of RTX and those Tensor Cores. Outside of DLSS, the biggest
feature for gamers and streamers is going to be NVIDIA Broadcast. It’s a standalone
application that gives access to three very useful AI-based features. One of which I personally
use almost daily—Noise Removal. It’s quite astonishing what this thing is able to filter
out for recording or gaming with your friends. Here’s a secret: Nvidia made a standalone
app just for this that works with GTX cards, but I wouldn’t recommend trying to game
and use it at the same time.
There are also two other features surrounding your camera usage. One is a virtual background
that provides the ability to remove your background without the need for a greenscreen setup.
Like most virtual background implementations, you’re going to want to ensure you have
a nice contrast between you and whatever is behind you for it to work the best. The other
feature is the ability for the camera to crop in on the image dynamically and follow your
face around. This is more useful for just chatting or artistic streamers rather than
gamers in my opinion.
The last RTX feature I’m going to touch on today isn’t even in use yet, and is waiting
on a feature from Microsoft to finally be available. That’s none other than RTX I/O,
which will plug right into Microsoft’s DirectStorage API. This is a feature designed for gaming
PCs running ultra-fast NVMe drives and should greatly reduce I/O overhead from the CPU.
It will allow data to be moved in a compressed fashion directly to the GPU, leaving the CPU
to handle other operations and letting the GPU handle the decompression. It’ll still
be a bit before we can finally see this one in action.
So what does it mean when NVIDIA says RTX is ON? Well, it could mean any one of the
things I’ve gone over in this video today. It could be one type of hybrid ray-tracing
feature, it could simply be DLSS like in the case of Red Dead Redemption 2, or it could
be a full-blown path traced game like in Minecraft with RTX. If you want to know which it is
you’ll have to be sure to check the game and see what it supports.
I hope you got something out of today’s video and leave feeling a bit more certain
about what is and what isn’t RTX. If you enjoyed it please leave a like and make sure
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