As it teased previously, Microsoft has detailed its DirectX 12 API at the GDC in San Francisco. This latest version of the Direct X API "provides a lower level of hardware abstraction than ever before, allowing games to significantly improve multithread scaling and CPU utilization," according to Microsoft. It dramatically improves rendering pipeline features. The other big new thing about DX12 is that it "works across all the Microsoft devices you care about," including PCs, the Xbox One and mobile devices.
Nvidia and AMD statements
Microsoft says that DirectX 12 will run on many graphics cards that are already on the market and built into the systems you already own. Both Nvidia and AMD issued statements about their support for DirectX 12:
Nvidia said that all of the DX11-class GPUs it has shipped (the Fermi, Kepler and Maxwell architectural families) will support DirectX 12. The green team says that over 70 per cent of gaming PCs are now DX11 capable and that its GPUs power more than 50 per cent of such systems.
DirectX 12 was demonstrated at GDC using a GeForce Titan Black running a tech demo of the Xbox One racing game Forza. Nvidia says it started working with Microsoft more than four years ago on how to make more efficient use of hardware.
AMD said that all its Radeon GPUs which feature the Graphics Core Next (GCN) architecture will support DirectX 12. Not surprisingly AMD has also been working with Microsoft in developing the new Direct X API.
Matt Skynner, corporate vice president and general manager, Graphics Business Unit, AMD, said that "With the Mantle API, AMD has shown the world our commitment to incredible performance, and we look forward to enabling the same performance gains by supporting the industry-standard DirectX 12."
3D performance gains
Microsoft used 3DMark, ported to use Direct3D 12, to verify its new efficiency claims. Its demonstration showed a 50 per cent improvement in CPU utilisation and better distribution of the workload across processor threads. Check out the composite graph below.
Developers traditionally are able to squeeze more performance out of a console with its constant defined hardware than a PC but Microsoft claims the new Direct3D 12 "even in an alpha state, brings this efficiency to PC and Phone". The firm demonstrated this performance lift with a Forza 5 tech demo on PCs at GDC.
Microsoft explains the technicalities behind how it improved the performance in Direct3D under the headings of 'Pipeline state objects', 'Command lists and bundles' and 'Descriptor heaps and tables' on its DirectX blog if you wish to read more.
When will you see the first DirectX 12 games? Microsoft says that it is "targeting Holiday 2015 games". So that's next-next Christmas folks. ZDNet reports that Microsoft is "aware of requests for Windows 7 support with DirectX 12 but didn't commit to delivering it". Also it is thought that Windows 9 'Threshold' and Windows Phone 9 OSes will include the DX12 API.