For the first time in the history of video game consoles, it’s actually possible to do an almost direct comparison of the hardware inside the PlayStation 4 and Xbox One. In almost every one of the seven preceding generations, game consoles were outfitted with highly customised chips and CPUs featuring niche, specialised architectures that could only really be compared very generally (bits, flops) or in very specific terms (number of on-screen sprites, MIDI instruments, etc).
The PS4 and Xbox One, however, are very similar consoles. With an x86 AMD APU at the heart of each, the Sony and Microsoft consoles are essentially PCs – and their hardware specs, and thus relative performance, can be compared in the same way that you would compare two x86 laptops or ARM Android tablets.
Xbox One versus PS4: CPUs compared
For the PS4 and Xbox One, Microsoft and Sony both opted for a semi-custom AMD APU – a 28nm part fabricated by TSMC that features an 8-core Jaguar CPU, paired with a Radeon 7000-series GPU. We’ll discuss the GPU in the next section. As far as we know, the PS4 and Xbox One CPUs are virtually identical, except the Xbox One is clocked at 1.75GHz, while the PS4 is at 1.6GHz.
The Jaguar CPU core itself isn’t very exciting. In the PC world, Jaguar is used in AMD’s Kabini and Temash parts, which are aimed at laptops and tablets respectively. If you’re looking for a tangible comparison, CPUs based on the Jaguar core are roughly comparable to Intel’s Bay Trail Atom.
Ultimately, despite the Xbox One having a slightly faster CPU, it is very unlikely that the CPU will make a big difference to either console’s relative gaming performance. There is perhaps one key difference between the two consoles, though: Earlier in the year, Microsoft told developers that games will only have access to six of the CPU cores, presumably because two cores are reserved for other tasks. We don’t know if this is still the case, and we also don’t know if the PS4 has a similar restriction in place. Either way, it probably won’t be significant – relative GPU performance will probably be the major differentiator between the two consoles.
Xbox One versus PS4: GPUs compared
Again, by virtue of being an AMD APU, the Xbox One and PS4 GPUs are technologically very similar – with the simple difference that the PS4 GPU is larger. In PC terms, the Xbox One has a GPU that’s similar to the (entry-level) Bonaire GPU in the Radeon HD 7790, while the PS4 is outfitted with the (mid-range) Pitcairn that can be found in the HD 7870. In numerical terms, the Xbox One GPU has 12 compute units or CUs (768 shader processors), while the PS4 has 18 CUs (1152 shaders). The Xbox One is slightly ahead on GPU clock speed (853MHz versus 800MHz for the PS4).
In short, the PS4’s GPU is – on paper – 50 per cent more powerful than the Xbox One. The Xbox One’s slightly higher GPU clock speed might ameliorate some of the difference, but really, the PS4’s 50 per cent higher CU count is a serious advantage for the Sony camp. Furthermore, Microsoft says that 10 per cent of the Xbox One’s GPU is reserved for Kinect. PS4 games will have a lot more available graphics power on tap.
Beyond clock speeds and core counts, both GPUs are identical – they’re both based on the Graphics Core Next (GCN) architecture, and thus support OpenGL 4.3, OpenCL 1.2, and Direct3D 11.2. Another big difference between the two consoles is the available memory bandwidth – but we’ll discuss that in the next section. Details are fairly tenuous at this point, but we believe that the Xbox One – via Direct3D and GCN – will support AMD’s Mantle API. This gives developers lower-level access to the bare metal of the GPU, potentially improving performance. We don’t think the PS4 has access to the same resources.
Xbox One versus PS4: RAM subsystem and bandwidth
Once we leave the CPU/GPU, the hardware specs of the Xbox One and PS4 start to diverge, with the RAM being the most notable difference. While both consoles are outfitted with 8GB of RAM, the PS4 opts for 5500MHz GDDR5 RAM (similar to what you’d find on a modern graphics card), and the Xbox One uses 2133MHz DDR3 RAM (the same as the main RAM in your PC). This leads to an absolutely massive bandwidth advantage in favour of the PS4 – the PS4’s CPU and GPU will have 176GB/sec of bandwidth to system RAM, while the Xbox One will have just 68.3GB/sec.
In Microsoft’s favour, the Xbox One has 32MB of super-fast embedded SRAM (see the above Xbox One SoC block diagram – the 32MB of ESRAM is at the bottom in four blocks of 8MB, and provides about 102GB/sec in each direction, for a total of 204GB/sec of bandwidth).
If this ESRAM is used properly, as a cache, then it’s possible that the huge difference in main system RAM bandwidth can be ameliorated. This will most likely come down to individual developers (do they have the time and inclination to use the ESRAM?), and whether Microsoft makes it easy to use the ESRAM efficiently. It’s worth noting that the Xbox 360 used embedded DRAM, so it’s highly likely that Microsoft and developers will know how to make the most of it.
Xbox One versus PS4: What difference will the hardware specs make in games?
It’s nice to be able to compare hardware specs in a straightforward fashion – especially if you’re a PlayStation fan, as it clearly beats the Xbox One on paper. When it comes down to it, though, the specs mean nothing on their own: It’s entirely down to how Microsoft, Sony, and game developers actually use the hardware.
To begin with, we would expect games on the PS4, with its beefier GPU and simpler memory subsystem, to be smoother and prettier. We have already seen this borne out by games such as Battlefield 4, where the PS4 outputs at 1600 x 900, but the Xbox One outputs at just 1280 x 720 – a difference that is almost perfectly explained by the PS4’s 50 per cent more powerful GPU. The video below shows Battlefield 4 running on both consoles side-by-side:
Despite the resolution difference and upscaling, though, there is very little visual difference between the Xbox One and PS4. By virtue of being based on the same GPU architecture, games on both consoles will look very, very similar – the same lighting, the same textures (presuming the Xbox One’s lower bandwidth isn’t a bottleneck), the same smoke, and so on. If you are playing games from a reasonable distance (10 feet, 3 metres), you are unlikely to see much, if any, difference between the consoles.
That said, irrespective of whether developers can harness the Xbox One’s ESRAM, I don’t think Microsoft’s console will ever compete with the PS4’s larger GPU. I think the PS4 will always have the edge when it comes to raw graphics power, and thus a higher output resolution and smoother frame rates.
In reality, due to commercial restraints, I expect most cross-platform games will look virtually identical across the two consoles for their entire lifecycle. PS4 exclusives that take full advantage of the console’s superior hardware, though – such as masterpieces produced by Naughty Dog – will probably look significantly better than anything on the Xbox One.
For more on the next-gen consoles, see our article on the PS4's easily removable hard drive, and how Microsoft isn't playing ball with enthusiasts, along with our hands-on with the PlayStation 4.
You might also want to check out our closer look at the Xbox One and PlayStation 4's DRM, and our piece on the launch of the PS4 and Xbox One, and why you can expect problems from day one.
Image Credit: Wired