Next generation consoles and ray-tracing thoughts (update 1)17 Jun 2019
I've been working on a large project for a while now, so I haven’t been doing much else, which is the excuse for the lack of posts.
Since there’s been some updates, I thought I might as well quickly write something on next-gen console ray tracing again.
So, we’ve had E3, including Microsoft’s announcement of ‘Project Scarlett’ (video on Xbox.com).
- Zen 2 and Navi GPU from AMD.
- ‘From a pure processing prospective this is four times more powerful than the Xbox One X’.
- 120FPS and 8K support
- Variable refresh rate
- ‘Next-gen raytracing, it’s real time because it’s hardware accelerated for the first time ever’ (1:45)
- SSD, custom built, using as virtual RAM, more than 40 times the performance of current gen.
- ‘Your games, your achievements, your progression, your accessories, your console gaming experience with Xbox, it all comes forward with Scarlett’.
So, this is pretty much what we expected, especially given the Sony announcement.
The interesting part, and why I’m writing about it, is the ray-tracing part.
I didn’t think much of that part, until I saw some discussion later in the week where I noticed some people saying that Sony never said hardware accelerated.
Sony’s wired interview
So I decided to go back and re-read the Wired interview.
The first time raytracing is mentioned is here: ‘The GPU, a custom variant of Radeon’s Navi family, will support ray tracing, a technique that models the travel of light to simulate complex interactions in 3D environments.’
Note, it doesn’t say accelerated, just ‘support ray tracing’. Almost any GPU released in the last 10 years can ‘support ray tracing’ it’s just that they’re not fast enough for use in real-time games.
The next paragraph talks about how raytracing is used in Hollywood for effects in general, but not specifically the PS5.
Then comes a direct quote from Mark Cerny, ’ “If you wanted to run tests to see if the player can hear certain audio sources or if the enemies can hear the players’ footsteps, ray tracing is useful for that,” he says. “It’s all the same thing as taking a ray through the environment.” ’
This is interesting because it’s the simplest thing you could do with raytracing and needs very little processing power. There’s already engines that do this on the CPU, so it seems a weird example to use, unless it’s all you can do and you just want to be able to put ‘supports raytracing’ on the box without doing what people expect.
We also had the AMD event at E3 where they announced a load of stuff, including the first Navi GPUs, which, don’t support hardware acceleration of raytracing.
The interesting thing is, all the rumours and leaks so far have suggested that both the next-gen consoles are using first generation RNDA cores which will be using the same technology as this. The suggestion has been that both companies are aiming to have the hardware finished earlier than previous generation to give developers more time before launch.
We know there are dev-kits out there already and this is where things get tricky. You tend to get two types of these. Some are basically PCs that are powerful enough to be similar to what the console will be, but not the same hardware, in this instance probably a gen 2 Ryzen and Radeon VII GPU, and the devs are told what to aim for (clock speeds can be reduced if necessary). The other are pre-production hardware, so things like the clock speeds won’t be final but it’ll be in the general area.
Both companies have slightly different hardware for dev-kits, Sony tend to have a separate design (with extra memory and interfaces for debugging), while Microsoft go with one that’s much closer to normal hardware, as their debugging interfaces are based off the Windows ones which don’t need extra hardware.
Navi not having any acceleration of ray tracing would suggest that AMD didn’t know about DXR/RTX until after the public announcement, so we’re probably looking and next year being the earliest they’ll have a product out that does.
This leads to four obvious outcomes:
- The article is just badly written, and even though it would definitely have been cleared by Sony before release, they will have acceleration.
- Sony have chosen Navi 1, and are stuck with it, so they’ll mention ray tracing now, and have a software-based implementation that won’t be used much but will exist and ship that.
- Same as above, but now knowing that Microsoft have a feature they don’t, push to get theirs available first, and go for an early release (say mid 2020).
- AMD have said Navi 2 will have something, but it’s not ready yet, so they’re waiting until it’s available, possibly delaying the console until after Microsoft’s, which is why we have no vague launch date yet.
It’s going to be an interesting generation, and we’ve probably got a year to wait (next E3) before we hear much more, unless they choose option 3.