Microsoft revealed Xbox One X’s specification via Digital Foundry in April. They confirmed specs announced at last year’s E3 presentation. 6 teraflops of GPU raw power, faster CPU and 12 GB of super fast GDDR5 memory. But this is not all that we have learned about this console. Microsoft also shared their “Scorpio Engine” tech which is the heart of a system features around 60 hardware customizations. In this article I would like to share some of these with you. So let’s dive into it.
Before I go into more details, let me explain what “Scorpio Engine” is. It’s a SoC – System On Chip – and it’s basically a CPU, GPU and memory controllers on one chip. Therefore even though I will be referring to CPU & GPU as separate parts – these are not separate. These are only different parts of the same chip.
AMD’s Jaguar based CPU part clocked at 2.3 GHz offers more than a 30% boost in comparison to Xbox One’s 1.75 GHz CPU. On top of that Microsoft confirmed CPU performance optimizations revolving around memory latency improvements of the main memory controllers. They also rearranged and enlarged the translation lookaside buffer cache and introduced redesigned and larger Page Descriptor Cache. These customizations offers significant performance boost according to Microsoft. Also, we cannot forget about the DirectX 12 hardware component that may take over some of the CPU tasks like making draw calls. Processing draw calls usually takes up a large portion of the CPU performance. If developers will offload it to the GPU’s Compute Units, the CPU will have more resources to deal with physics, AI, data compression and decompression.
AMD’s Polaris-based GPU part offers 6 teraflops of raw performance. They achieved this by packing four shader arrays that each offer 10 compute units. 40 customized compute units running at 1172MHz offers a 4.5 boost over the base Xbox One’s GPU which allow developers to make their games in native 4K resolution and some will even run at 60 frames per second. But there is more to the GPU than teraflops alone. Polaris architecture is much more efficient so you basically get more performance in comparison to the older Xbox One’s GPU per teraflop. Some of the big Polaris features are delta color compression which helps to save some bandwidth, both for 4K textures and 4K rendering solutions. Other features worth mentioning are geometry and quad-scheduling improvements. There are also some small VEGA architecture-based improvements which Microsoft never named specifically. Overall there are 60 or so specific targeted changes throughout the pipeline. Everything from various memory sizes, queue sizes, features to make sure that backward compatibility went as smoothly as possible as well. All this to make sure a smooth 4K experience is being delivered.
Microsoft packed 12GB of super fast GDDR5 memory into their upcoming console. 326 GB/s peak memory bandwidth should move data around the system fast enough to deliver a 4K experience. They got rid of ESRAM which is a bit of a pain to optimize for. Instead they reserved 40MB of main memory space to emulate the ESRAM. On top of that they introduced a new memory controller which should improve data flow around the system.
All above mentioned customizations have been made with software in mind. Microsoft didn’t want to introduce any new features that would require developers to spend even more time optimizing the code for this particular feature. They wanted to improve the hardware in a way that it handles current game engines better without too much of optimization. Microsoft come up with some parts of the design. Microsoft engineers handed logic to AMD for integration.
So Xbox One X “Scorpio Engine” is a heavily modified and customized chip. You will not find anything like that on the market except for the Xbox One X. And it looks like it paid off for Microsoft with games like Forza Motorsport 7 and Rise of the Tomb Raider showing what their new console is really capable of. Now it’s up to developers how they utilize the power in their games. And ultimately it will benefit us as we will just get better games.