Rebellion has published a patch as well as a rather long blog post announcing explaining its support for AMD Mantle API in its latest Sniper Elite III game. According to the early results published by Rebellion the performance benefits of the Mantle API, compared to the DirectX 11, are quite impressive.

The blog post published by Rebellion was authored by Kevin Floyer-Lea, Head of Programming at Rebellion Developments, which shows that the in-house Asura engine used in Sniper Elite III can certainly benefit from the added support for AMD's Mantle API, both for that game as well as any future games. The early results, taken from the "Siwa" level in Sniper Elite III, shows that there is certainly a decent performance improvement with AMD Mantle, when compared to the same game running on the same hardware and DirectX 11, especially when it comes to CPU overhead.

The results are especially impressive if you consider that the aim was to reuse exactly the same data and assets that were used in already available DirectX 11 version of the game, so there were no optimizations done on shaders, data formats or rendering techniques.

The AMD Mantle API optimized version of Sniper Elite III not only provides the higher frame rate but also lower CPU overhead when running on the same hardware. The screenshot below shows that you get a much more balanced CPU load across all eight cores on the Core i7-3770K CPU used for testing. While the aforementioned Asura engine is already optimized for DirectX 11 weaknesses by using certain batching techniques, there was still a decent frame-rate increase when Mantle was implemented.

According to Rebellion, AMD's Mantle API implementation in Sniper Elite III has delivered all that they hoped for including an improved frame-rate, reduced CPU power consumption (important for laptops), made the game less susceptible to frame-rate spikes when other programs hit the CPU. Mantle also added future scalability with a higher numbers of cores, more scope for increasing scene and world complexity and the ability to increase the CPU budget for other game sub-systems like AI. While some of these improvements can be seen with Sniper Elite III game, others are more important for future games that will be based on te Asura engine.

In any case, it will be quite interesting to see how many more Mantle API wins will AMD manage to get and how the API will compare to DirectX 12 when it lauches with Windows 10 next year.