At Game Developers Conference, Microsoft detailed DirectX 12. Promising a "console-like API," the key feature of DirectX 12 is Direct3D 12, which Microsoft's Anuj Gosalia jokingly described as "more Direct than ever." As expected, it will run across "all Microsoft platforms," including "the lowest of smartphones, to game consoles, to the highest-end graphics cards."

Direct3D 12 will allow developers to "fully exploit the GPU." As a result of the update, Gosalia promises that Xbox One games will see "increased performance."

In a 3DMark demo, performance increased significantly simply by moving to D3D12 code, with no optimization. With D3D12, multi-threading is more scalable, with asynchronous command list submissions and "near-perfect scaling" across CPU cores. In the demo shown during the presentation, a jungle scene was rendered in 3D, with resources almost evenly divided across the four CPU cores.

D312 is a "lower-level API," which will allow "console-like development." Turn 10 Studios' Chris Tector took the stage to talk about porting Forza 5 to DX11, but there was too much CPU overhead. However, porting the game to D3D12 made it possible. It took a 4 man-month effort to port the rendering engine from Xbox One D3D11.X to D3D12.

The Forza 5 rendering demo showed a P12 driving around, hitting a very steady 60fps. "We're very excited to see console-style development on PC through D3D12, and we're especially excited to see these features come back to Xbox One," Tector said. Unfortunately, no PC port of Forza 5 was announced.

On day one, all Nvidia DirectX 11 hardware will support DirectX 12. "We've already delivered DirectX 12 drivers to developers already," Nvidia's Tony Tamasi announced at the panel.

For mobile, DirectX 12 offers a number of benefits. "We have a lot of cores as well," Qualcomm's Eric Demers pointed out. He says that DX12 will offer "improved power efficiency," with more efficient use of multicore CPUs with the new D3D12 runtime. "We're excited about seeing Xbox and PC titles moving to the mobile platform," Demers added, saying that a unified runtime will ease ports.

Gosalia says that by release, about 50% of gaming PCs should be able to run DirectX 12, joking that "100 percent of Xbox Ones" will support the API. DX12 is targeting "Holiday 2015," however early access preview releases will be available later this year.

However, what OSes will DX12 land on? "We understand your desire to get DirectX on the broadest amount of platforms," Gosalia said, but he refused to say anything specific regarding Windows 7. He did confirm Windows XP won't be supported after a joking question from the audience. "You'll be hearing more from us soon," he said.