It’s been just over a year since AMD launched its next-generation Mantle API, with the promise that low-overhead gaming would dramatically boost frame rates and lead to fundamentally new types of game engines. One of the demos that Sunnyvale used to show off its new API was Star Swarm, a tech demo and next-generation engine from Oxide Games. Now, a new head-to-head comparison puts AMD and Nvidia head-to-head in the test — only this time, they’re both running under DirectX 12.

The performance data in Anandtech’s comparison should be taken with a significant grain of salt. D3D12 support is baked into Windows 10, but the code is early. The drivers from AMD and Nvidia are pre-production, obviously, and the underlying OS it itself in a pre-RTM state. Windows 10 uses version 2.0 of the Windows Display Driver Model (WDDM), which means that a great deal of under-the-hood work has changed between Windows 8.1 and the latest version of the operating system. The preview is quite extensive, they test the GTX 980 against multiple AMD cards in multiple CPU and GPU configurations and I don’t want to spoil their thunder. At the Extreme preset we see several interesting results:

The first thing people are going to notice is that the GTX 980 is far faster than the R9 290X in a benchmark that was (rightly) believed to favor AMD as a matter of course when the company released it last year. I’ll reiterate what I said then — Star Swarm is a tech demo, not a final shipping product. While Oxide Games does have plans to build a shipping game around their engine, this particular version is still designed to highlight very specific areas where low-latency APIs can offer huge performance gains.

As impressive as the GTX 980’s performance is, I’m going to recommend that nobody take this as proof that Nvidia’s current GPU will blow the doors off AMD when D3D12 is shipping and games start to appear late this year or early next.

The second thing that some users will note is that the R9 cards offer very similar performance in Mantle vs. DirectX 12, at least for now. There was always some discussion over whether or not Mantle and D3D would offer similar performance capabilities, and at least for now, it looks as though they may — though again, that should be taken as a tentative conclusion.

AT steps through multiple benchmarks and comparisons between the two GPU families, as well as simulated performance on dual and quad-core configurations. There’s no comparison of AMD hardware, which makes sense on the one hand — AMD CPUs are not widely used for enthusiast gaming these days — but is unfortunate on the other. Mantle has always had its best showing when used to accelerate the performance of AMD CPUs or APUs, and it would’ve been interesting to see if Direct3D 12 benefited its hardware as much as its own native API has done.

Microsoft confirms: DirectX 12 will be a Windows 10 exclusive

One point update that Anandtech disclosed as well is that Windows 10 and DirectX 12 will be bundled together — D3D 12 will not come to Windows 7, 8, or 8.1. The free upgrade offer on Windows 10 will doubtlessly blunt a great deal of criticism that MS would otherwise have come in for, but users who can’t upgrade or simply don’t want to won’t be happy.

Whether or not this will breathe life into AMD’s Mantle is an interesting question. In theory, Mantle could see increased adoption if the MS userbase digs in its heels over Windows 10 the way it did over Windows 8. On the other hand, it’s possible that we’ll see increased support for the next-generation OpenGL standard (dubbed GLNext) as an alternative to DX12 and Windows 10.

More details on both DX12 and GLNext will be released at GDC this year, which kicks off in early March.

Now read: Most DirectX 12 features won’t require a new graphics card