What Xbox 'Project Scorpio' means for PC gaming

Microsoft has dished the deets on its upcoming 'Scorpio' hardware update for the Xbox console, and in what amounts to uncharacteristic detail and candour given the ruddy thing isn't going on sale until the end of 2017. But what are we poor PC peasants to make of the Beast of Redmond's latest game box and its towering on-paper capabilities? In short, what influence will Project Scorpio's trick new hardware have on future PC games?

As ever with such developments, there is no single and simple answer. Scorpio's hardware is at the very least a tale of two halves even if they are crammed into a single computer chip or SoC. I speak, of course, of the critical CPU and graphics elements.

The media razzmatazz has largely centred on the graphics half of the equation and there's no denying Scorpio packs some serious pixel-pumping power for a grotty little games console. The headline figures for the GPU rock in at 40 so-called compute units running at 1,172MHz. That compares with ye olde Xbox One's 12 units at 853MHz and the One S with the same number again, albeit running at 914MHz.

It's AMD, of course, who supplies both the graphics and the CPU designs for the Xbox and, in the Red Team's standard parlance, a compute unit packs 64 of those, er, shader thingies that make the pixels look so very pretty. We're talking 768 shaders in the Xbox One and 2,560 of the bump-mapping blighters in Scorpio.

If that sounds impressive, AMD's current fastest GPU, the elderly Radeon R9 Fury X packs 4,096 shaders. And lest you forget, the Fury X is a generation behind and not nearly as fast as Nvidia's best GPU du jour, the preposterous Titan Xp.

On the CPU side of the Scorpio equation, Microsoft has stuck with eight low-power AMD Jaguar-derived cores, albeit running upclocked from 1.75GHz to 2.3Ghz and benefiting from several detail tweaks. The other major part of the package involves the memory and bandwidth combo, which in these consoles is a little more complex given the single-chip architecture means shared memory for GPU and CPU. Anyway, there's a healthy uptick here too, from 218GB/s and 8GB to 326GB/s and 12GB.

The very first observation to make is that while Scorpio moves the game on massively for consoles, it is not exactly frightening today's high-end PC hardware, much less what will be available when Scorpio actually arrives and, in turn, the PC hardware that will appear over Scorpio's lifetime.

For some perspective, consider that main Scorpio CPU-GPU-SoC thing as a whole clocks in at seven billion transistors. That's for everything – the CPU, the graphics, the other SoC gubbins, the lot. Nvidia's biggest GPU, as found in the silly new Titan Xp and indeed the slightly more sensible 1080Ti, packs no fewer than 12 billion transistors. Add billions more for Intel's finest CPU and a bleeding edge PC's CPU and GPU alone are more than twice as complex.

Even the next tier down in Nvidia's GPU range, the GTX 1070 and the vanilla GTX 1080 are alone about on a par for complexity with the unified Scorpio chip. So while consoles tend to do more with less, there's a limit to that philosophy. The PC's performance and fidelity advantage isn't being challenged.

That's especially true when it comes to the CPU side of things. Put simply, Scorpio's CPU cores continue to suck. A fair bit of Microsoft guff has been regurgitated by the tame media regarding Scorpio's modified cores, the reduced internal latency, 31 per cent faster core clocks, how the new SoC is more customised than before. But I'm not terribly impressed. Clearly, they're still mostly the the same crappy low-power cores as before, not proper desktop cores.

Ermegerd, is that a magnetic hard drive?

Put another way, remember what a kicking AMD got for the poor performance of its outgoing FX PC processor? Well, it's a hell of a lot better than the CPU in any Xbox, including Scorpio. Even AMD's new Ryzen CPU has been taking a bit of a beating for supposed iffy gaming performance. It would completely obliterate the feeble cores in Scorpio.

That's the disappointing bit, then: That the initial development target for a lot of games for several years to come will still be a system with pretty pathetic CPU cores. The rub here is that while it's relatively straightforward to add at least some graphical detail to a game when porting for the PC (just chucking in some high res textures can do a power of good for the look of a game), taking advantage of additional PC processor power tends to require a more fundamental rethink of the game engine and indeed the game itself. Which, let's be honest, isn't usually going to happen.

The exception to all this and what might - just might - prove a saving grace, is the new so-called GPU Command Processor in Scorpio. It's basically a section of dedicated circuitry on the main SoC design to run DirectX 12 API invocations. In English? Think of it as a DX12 hardware accelerator for some of the more CPU-intensive bits of the game engine like draw calls. It could be a game changer by freeing up even Scorpio's weak CPU cores to do interesting and innovative things. But it's far too early to say for sure.

If that's the bad and yet-to-be-proven news, the good is that Scorpio's focus on pukka 4K capability means that developers will put a lot of effort into making games look great at high resolutions. To pinch a quote from Kevin Gammill, Group Program Director of the Xbox Core platform, “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.”

In other words, proper high-res textures, geometry and effects that on the one hand really make the most of the detail 4K can deliver and on the other are optimised to reduce performance overheads. And, of course, Scorpio should accelerate the development of games with proper HDR support, which is just another string in developer's bows when it comes to making games look awesome.

Of course, you very likely don't have a 4K PC screen and you almost certainly don't have an HDR monitor. But all that should still benefit PC-relevant resolutions like 2,560 by 1,440, otherwise known as 1440p, that sit in between full 4K and 1080p.

One part of the Scorpio graphical package for which the benefits to the PC remain to be seen involves tweaks to the graphics engine that go beyond simply adding more functional units. Apparently, Microsoft and presumably AMD took a good look at how developers actually make game engines and then tweaked detailed aspects of the graphics architecture to suit.

That's not going to help existing PC graphics cards. But will we see any of those same hardware tweaks in AMD's new Vega GPUs, due later this year? My guess is that we may see some similar elements, but probably not everything. So the benefit-cost calculation for the PC in that regard remains to be seen.

Overall, Scorpio looks like it'll be a great thing for PC gaming in terms of plain old eye candy. Whether it will enable more innovation and complexity at the core of game engines is a tougher question and will likely depend on how that funky hardware DX12 setup engine in the Scorpio SoC pans out. Watch this space.