Futuremark has updated the Advanced Edition and Professional Edition versions of its 3DMark benchmarking software that adds an API Overhead feature test that supports DirectX 12 in the latest 10041 build of the Windows 10 Technical Preview.

The API Overhead feature test is the same one Microsoft used at its January Windows 10 press event to show off the improvements in its DirectX 12 game graphics API compared to the current DirectX 11. It's now being released for the first time, and is also the first public application ever that uses DirectX 12. It also supports DirectX 11 and AMD's Mantle API.

Futuremark reveals just what the API Overhead feature test is supposed to benchmark:

There has been much talk this year of new graphics APIs that let developers code 'close to the metal.' And though it's natural to think of the GPU, the benefits of APIs with lower overhead are actually achieved by making better use of multi-core CPUs to streamline code execution and eliminate software bottlenecks, particularly for draw calls.

A draw call happens when the CPU tells the GPU to draw an object on the screen. Games typically make thousands of draw calls per frame, but each one creates performance-limiting overhead for the CPU. With more draw calls, a game engine can draw more objects, textures and effects to the screen.

The 3DMark API Overhead feature test measures API performance by making a steadily increasing number of draw calls. The result of the test is the maximum number of draw calls per second achieved by each API before the frame rate drops below 30 fps.

Futuremark adds that this new test is not a GPU-based benchmark and should not be used to compare different graphics cards running on DirectX 12. The company is working on a GPU-based DirectX 12 benchmarking program that will be released sometime after the official launch of Windows 10.

Besides the need for build 10041, Windows 10 preview users will also need to have at least 4GB of RAM in their PC to run the benchmark, along with "DirectX feature level 11_0 compatible hardware with at least at least 1 GB of graphics memory." Be aware that the test has been placed in the Advanced version of 3DMark, which costs $24.95, and the Professional version, which cost $995. It is not included in the free version of 3DMark.

Source: Microsoft, Futuremark