3DMark API Overhead feature test – the world’s first independent test for measuring differences in DirectX 12, DirectX 11 and Mantle API performance. Developed with input from AMD, Intel, Microsoft, NVIDIA, and the other members of our Benchmark Development Program, the 3DMark API Overhead feature test lets you compare the performance of DirectX 12, DirectX 11, and Mantle.
The purpose of the test is to compare the relative performance of different APIs on a single system, rather than the absolute performance of different systems. The API Overhead feature test is not a general-purpose GPU benchmark, and it should not be used to compare graphics cards from different vendors. (We are working on a DirectX 12 benchmark with game-like workloads, which we expect to release soon after the public launch of Windows 10.)
Why is API overhead important?
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.
As the number of draw calls rises graphics engines become limited by API overhead. New APIs like DirectX 12 and Mantle reduce that overhead allowing more draw calls. With more draw calls, the graphics engine can draw more objects, textures and effects to the screen.
How does the 3DMark API Overhead feature test work?
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.
Here’s what the benchmark is like.
If you are unable to view the video, here’s a summary of the test I conducted.
Sorry, I do not have a Windows 10 machine at the moment. 😛 Judging from the report of others with Windows 10 setup, the DirectX 12 performance is slightly behind that of MANTLE.
What are the system requirements?
– The DirectX 12 test requires a PC running an up-to-date version of Windows 10 Technical Preview (Build 10041 or later), 4 GB of system memory, and DirectX feature level 11_0 compatible hardware with at least at least 1 GB of graphics memory.
-The Mantle test requires 4 GB of system memory and AMD hardware that supports the Mantle API.
-The DirectX 11 test requires DirectX feature level 11_0 compatible hardware with at least 1 GB of graphics memory and 4 GB of system memory.