updated 11:30 pm EST, Sun February 2, 2014
Mantle API to put developers in closer communication with GPU
After a short delay due to packing issues with the installer, the newest 14.1 beta version of the Catalyst drivers for AMD video cards has gone live this weekend. While most driver releases come and go without much fanfare, this specific driver release is important, as it features the first time consumers can get their hands on the highly-anticipated Mantle API.
Mantle has been on the tip of the tongues of many people in the gaming community since AMD announced the API to challenge OpenGL and DirectX in October 2013. Speculation about what Mantle would actually accomplish for developers and users since then has been surging, but a tangible product has finally been released for people to make their own judgments.
The core of the Mantle API's strength is that it allows developers to have their programs call directly to AMD GPUs and APUs instead of having to pass many of the instructions through a CPU first. This frees up computing power, allowing developers to demand more performance from applications. The transition to more GPU use and direct calls brings the PC more in line with the current generation of consoles, which also happen to be powered by AMD.
AMD gamers won't see the true power that Mantle has in unlocking performance outside of the game Battlefield 4 at present, as it is the only game that supports it on the market. However, the future looks promising, with games like Thief and Star Citizen already being built with support for the API. AMD states that an application needs to be written to take advantage of Mantle, so widespread support may take longer to hit the market. Developers will also be responsible for new tasks such as frame pacing, which may be a factor that limits development towards the platform.
More direct access to GPUs may have a secondary effect, making processes aimed in mathematical computations more efficient as well. Bitcoin mining and supercomputer number-crunching may see new strides through Mantle.
Top end PCs using maximum settings will likely see only minimal improvements, as Mantel main focus isn't to improve the processing power of the graphics side of things, but rather to alter the normal assignments to the CPU. The majority of applications are tied to the processor, thus creating a bottleneck at the hardware level when the application doesn't hand off workloads properly to separate cores within it.
This has been a widespread problem in the PC industry since the first consumer dual-core processors hit the market in 2004. Lower powered processors with much more to gain from processor offload will see much larger improvements, especially in systems using APUs.
According to data from AMD, APU-based systems using the A10 7700K appear to have the greatest improvements in Battlefield 4 over DirectX, but true improvement results will need to wait until benchmarks can be completed. Greater results will be seen in the newest of the AMD cards, including the Radeon 260s and 290s, and in Kaveri based APUs.
The Catalyst 14.1 driver featuring Mantle is currently in beta, so bugs are still being worked out. At the time of release, the drivers were known to have issues with CrossFire setups and a small number of issues with the already bug-plagued Battlefield 4.