Today, we finally know what makes the upcoming Microsoft console code named Project Scorpio tick, with Eurogamer revealing the specs of the console that will be released this Holiday season.
First of all, you can check out the specs below, compared with the massively overwhelmed Xbox One and Sony’s top of the line console, the PS4 Pro. We can certainly see that Microsoft’s console is superior across the board to the competition.
If you’re wondering, the combination of horsepower and architecture design does match the six teraFLOPS promise made at E3 last year. According to Eurogamer’s tech arm Digital Doundtry, a Forza Motorsport demo ran at 60 FPS in native 4K with power to spare (in the gallery at the bottom of the post, you can se 68.19% GPU utilization), suggesting that the console will support the resolution across its content, without forgetting those running on 1080p monitors, that will get improvements as well.
The console comes in a compact design with integrated power supply and cutting edge cooling tech.
Xbox Core platform Group Program Director Kevin Gammill explains what the console is set to offer:
“To me, [4K] means a very specific set of things. It’s a lot more than delivering than those eight-million-plus pixels to the screen while playing games. It’s about delivering those pixels with 4K assets, so they look great. It’s about delivering those pixels with HDR and wide colour gamut fidelity. It’s about delivering those pixels with no loss of frame-rate compared to the 1080p version of that title – that’s super-important to us. Spatial audio adds to the immersive experience as well: to truly land that gameplay experience, it’s not just about what you see, but what you hear.”
“As we landed on 4K, Andrew [Goossen] and team did a pretty deep analysis. We have this developer tool called PIX [Performance Inspector for Xbox]. It lets us do some GPU trace capture. He and his team did a really deep analysis across a breadth of titles with the goal that any 900p or better title would be able to easily run at frame-rate at 4K on Scorpio. That was our big stake in the ground, and so with that we began our work speccing out what the Scorpio Engine is. It’s not a process of calling up AMD and saying I’ll take this part, this part and this part. A lot of really specific custom work went into this.”
Graphics Technical Fellow Andrew Goossen explained how Microsoft managed to make games designed for Xbox One work on the Scorpio’s new specs, years before a prototype the console was even built.
“What we did was to take PIX captures from all of our top developers… By hand we went through them and then extrapolated what the work involved would be for that game to support a 4K render resolution- Now we had a model for all of our top-selling Xbox One games where we could tweak the configuration for the number of CUs, the clock, the memory bandwidth, the number of render back-ends, the number of shader engines, the cache size. We could tweak our design and figure out what was the most optimal configuration. It was incredibly valuable for us to be able to make those trade-offs, because ultimately these Xbox One titles are the ones that we… wanted to get up to 4K.”
“We also leveraged the fact that we understand the AMD architecture really, really well now and how well it does on our games. so we were able to go through and examine a lot of the internal queues and buffers and caches and FIFOs that make up this very deep pipeline that, if you can find the right areas that are causing bottlenecks, for very small area [on the processor] we could increase those sizes and get effective wins.”
Goossen also explains that engineers did fine configurations beyond the superficial specs to achieve the console’s power.
“Those are the big ticket items, but there’s a lot of other configuration that we had to do as well. As you can see, we doubled the amount of shader engines. That has the effect of improvement of boosting our triangle and vertex rate by 2.7x when you include the clock boost as well. We doubled the number of render back-ends, which has the effect of increasing our fill-rate by 2.7x. We quadrupled the GPU L2 cache size, again for targeting the 4K performance.”
Silicon Distinguished Engineer Nick Baker also mentions that memory bandwidth is also crucial to stream the much larger textures included in 4K-quality assets.
“For 4K assets, textures get larger and render targets get larger as well. This means a couple of things – you need more space, you need more bandwidth. The question, though, was how much? We’d hate to build this GPU and then end up having to be memory-starved. So all the analysis that Andrew was talking about, we were able to look at the effect of different memory bandwidths, and it quickly led us to needing more than 300GB/s memory bandwidth. So in the end we ended up choosing 326GB/s. On Scorpio we are using a 384-bit GDDR5 interface – that is 12 channels. Each channel is 32 bits.”
Interestingly, we learn that of the 12 gigabytes of RAM included in the Scorpio’s architecture, 8 are usable by developers, and 4 are reserved to the system, this is necessary to run the dashboard in 4K, but games can still benefit from 60% more memory.
Scorpio does not use AMD’s new Ryzen technology, but there is still plenty more performance compared to the Xbox One in the console’s X86 cores, which are 31% faster, as explained by Baker.
“So, eight cores, organised as two clusters with a total of 4MB of L2 cache. These are unique customised CPUs for Scorpio running at 2.3GHz. Alluding back to the goals, we wanted to maintain 100 per cent backwards compatibility with Xbox One and Xbox One S while also pushing the performance envelope.”
We also get an upgraded audio processor that adds “spatial surround” to the 7.1 setup of the older console, adding a component for height. Dolby Atmos for gaming, Dolby Atmos for headphones and a Microsoft proprietary format called HRTF (developed by the Hololens team) will be supported.
An interesting development is that Direct3D 12 was moved into the command processor of the GPU, improving the efficiency of the communication from the game engine to the GPU itself, as illustrated by Goossen.
“We essentially moved Direct3D 12. We built that into the command processor of the GPU and what that means is that, for all the high frequency API invocations that the games do, they’ll all natively implemented in the logic of the command processor – and what this means is that our communication from the game to the GPU is super-efficient.”
“It’s a massive win for us and for the developers who’ve adopted D3D12 on Xbox, they’ve told us they’ve been able to cut their CPU rendering overhead by half, which is pretty amazing because now the driver portion of that is such a tiny fractio.”
The reason why the Ryzen tech hasn’t been used is simple: price. The console will still be a consumer product, and while the price itself has not been revealed, Gammill points out that Microsoft wants to have a price points that will encourage purchases.
“On the CPU side of things, we could still meet our design goals with the custom changes we made. At the end of the day we are still a consumer product. We want to hit the price-points where consumers want to purchase this. It’s about balancing the two.”
Xbox GameDVR has also been upgraded to 4K/60 FPS using the HVEC codec, which is also able to capture video in full HDR.
The display output will obviously be HDMI 2.0. Supersampling for 1080p display is also mandated to all developers, so if you have an older TV you don’t have to worry about wasting power and money. All games are also required to run at the same frame rate or higher as on standard Xbox One.
General Manager of Xbox Hardware Design Leo Del Castillo explains how the high clock speeds were achieved while still preserving heat dissipating and power efficiency required for a compact console design.
“So really, between trying to target a compact design, and also strike overall efficiency and minimize power use, we do a lot of things that are special. One of the things we do is we basically fine tune the voltages for each of the chips and optimist them so the chips are getting exactly what they need to get the job done… That drives a much higher degree of efficiency into the system and allows us to get rid of a lot of wasted power that would otherwise come out as heat.”
The heat sink is a vapor chamber with a custom designed centrifugal fan that looks like a supercharger on a car or an intercooler. The power supply is a 245W universal voltage one described as the most efficient in Xbox history. The power socket is the same as the one on the Xbox One S, so you can simply swap your old console for a Scorpio without even removing the plug from the wall outlet.
The Forza Motorsport image that you’ll see in the gallery below is basically an Xbox One port running in 4K, 60 FPS, so it isn’t representative of the quality of the next Forza game, yet it runs with GPU utilization hovering around 60-70 per cent,
Turn 10 Studio Software Architect Chris Tecton explains how it works:
“We’re still running with settings that we would have used in Forza 6… but this is also including 4K content… we’ve got authored assets for this set of the models, cars, tracks everything. We pushed it through and made sure the 4K textures were flowing through. We’ve got them all there at the right resolutions and they’re not giving us enough of a bandwidth hit to offset that. If we drop back to when we originally ran and we didn’t have 4K assets, it was maybe one per cent different. We were very much bound on a different point than memory bandwidth. It’s been awesome and this is the point it’s at.”
Interestingly, when the demo is pushed to the equivalent of Ultra-level settings on PC, CPU utilization remains at 88%, which is certainly impressive. This leaves the team time to improve image quality before release.
“The awesome part about the whole story [is] that we can spend all this time heading into the future. Instead of saying, ‘How are we going to wrestle to get the performance on this?’ we’re actually saying we can make this quality trade-off or this quality trade-off and spend that time iterating, heading towards much better image quality. So instead of stressing about getting to a final resolution or a final frame-rate, we can really drive it all into quality.”
If this is too much to process, you can also check out the video below, with Digital Foundry’s Richard Leadbetter giving the low-down on the console.