A user on Reddit has got his hands on preview build of Windows 10 which has DX12 functional. There has been a lot of talk regarding the amount of performance improvements that the API brings in, so the user tested out his 3 year old GPU, the Nvidia Geforce GTX 670 and Intel i7-2600k on this build and the results were surprising. He revealed that his tests gave a boost of close to 400% in draw call throughput.
As seen from the image below, results of DX 11 on a single thread were 1,515, 965 draw calls whereas on a multi-thread it was 2,532, 181 draw calls. However, when the user switched to DX 12, the number of draw calls increased to 8,562,158 which is more than 330% increase in performance.
He stated that he was surprised that DirectX 12 is already working well despite it being preview build. He also explained how the benchmark software is calculating the improvement in performance. “There’s no actual point score. All it’s doing is increasing the number of draw calls by increasing scene complexity. It just keeps going until the framerate drops to 30, then notes the calls/sec and bails. Since it’s only issuing calls for primitives (apparently anyways) it’s actually giving you a solid idea of how raw output is limited by the number of draw calls that can be dispatched.”
On asked how the new API will impact the Xbox One, he stated, “The problem there is the Xbone is hideously GPU bound and while multithreaded performance SHOULD be good, the CPU is operating at a painfully slow clock rate.”
On a related note, take this information with a grain of salt as this benchmark is not coming directly from Microsoft but given the numbers above closely resemble to those of the official benchmarks, the information is most likely legit. DX12 launches later this year.