During the Holidays, a hacker group leaked out the Xbox One SDK along with its complete documentation. The documentation revealed a few interesting tidbits such as Microsoft giving a 7th CPU core for developers to use and the different kind of updates such as graphics driver optimization that the Xbox One has received in the past. However it seems there are more details in the documentation, specifically related to the Xbox One’s GPU.

Discovered by a user on Beyond3d forum who pasted text from what seems to be from the SDK documentation, it has been revealed that the Xbox One GPU has eight graphics contexts. For those who are unaware, a graphics context consists of all drawing parameters and information to carry out commands related to drawing. It essentially consists of basic information such as color, width of the line, styling data and other relevant data. The Xbox One allocates seven of such graphics contexts to games.

It was also revealed that the console supports multiple GPU command streams which consists of instructions for rendering and compute. Both commands pass through the GPU simultaneously which allows to have two parallel processes of compute and rendering work, which share the same bandwidth resources. This results into a low latency exchange between GPU and CPU. However we are not sure whether developers can explicitly push one task type ahead of the other or whether the GPU automatically prioritizes the queue elements.

It must be noted that we are not sure whether the PlayStation 4 follows a similar implementation as the Xbox One. It will be rather intriguing to know how the PS4 reduces latency during CPU-GPU exchange.

Moving ahead. The document also revealed about how developers can use command lists and draw bundles to improve CPU performance, however these two methods won’t help much if a game is GPU bound. Both methods are recorded using deferred context. Deferred context is essentially keeping records of graphics commands in a command buffer so that they can be used at some other time as per requirement.

So if a game has already entered in rendering mode, but there are other rendering tasks which can be run parallely, developers can use deferred context using another CPU thread. The commands are then recorded and are executed using immediate rendering later. This same process can be supported multiple times over multiple CPU threads, thereby improving performance.

The recent Xbox One SDK and its respective documentation leaks have revealed new information about the different updates that Microsoft has applied to its Xbox One video game console. A few moments ago we reported on how the November SDK update unlocked more CPU power, but Microsoft actually implemented a few important upgrades in the October update as well.

This piece of information was revealed by a user on Union Video Game Forum who pasted screenshots from what looks like the Xbox One SDK documentation. Although most of the information in those screenshots are technical jargon, two pieces of information caught our eye. The October update has reduced the amount of memory utilized during runtime. Microsoft achieved this by updating the graphics driver so that memory overhead of vertex and pixel shader objects is reduced. According to tests, this saw a reduction of 45% in memory usage.

The other feature that the October update bought in was the inclusion of Descriptor Tables support. A descriptor table defines the characteristics of the various memory areas used during program execution, according to Wikipedia. Due to this, the shaders can  load resource descriptors from memory tables which can help reduce the CPU cost of rendering. What’s more? It’s ready for DirectX 12 as it can support the new API’s descriptor tables.

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As previously reported on, the hacker group known across the internet H4LT claimed responsibility for leaking the Xbox One Development tools alongside its documentation. However the documentation came along with a few surprises, revealing that a seventh core that was previously off limits to developers as it was reserved exclusively for running background operations, is now available for use, according to a report by EuroGamer.

Prior to the leaks, since October in fact, developers were allowed access to 50% to 80% to this seventh core which is likely responsible for the Xbox One having comparable performance with the PS4 for some games released in last quarter of 2014. However in order to achieve this performance boost, some features must be sacrificed such as the voice commands that are used with Kinect. This does however include the admittedly rather useful “Xbox Record That” feature.

It’s worth noting that an extra core to use doesn’t actually mean you’re guaranteed increased performance or better games, that falls to the development team and their use of the tools offered to them. With any amount of luck this will help bring the Xbox One back into the game a bit more.