Not dead yet: AMD’s Mantle powers new Vulkan API, VR efforts

Big changes have been afoot in the API world in the past 48 hours. First,Khronos announced the Vulkan API(aka glNext), which implements its own low-overhead API features, but offers support for the widest range of GPUs and operating systems. AMD also published its own blog post, openly telling developers who want to see Mantle-like performance to use either Vulkan or Direct3D. As a result, plenty of people have been trumpeting Mantle’s death and/or failure (typically with varying degrees of glee).

The actual situation is far more nuanced. Put simply, Mantle isn’t dying — but it’s definitely transforming into something different.

The future of Mantle

The first thing Mantle has transformed into is an API we’ve already spent time talking about yesterday — Vulkan. One thing we’ve known for months, and confirmed with developers independently, is that the Khronos Group’s Vulkan API is substantially based upon AMD’s Mantle. AMD's blog post states that “Khronos Group has chosen the best and brightest parts of Mantle to serve as the foundation for Vulkan.”

It’s not clear how much of Mantle was literally copied into the Vulkan API. But we’ve been told that the two APIs enable identical capabilities and are capable of the same things. The differences between them are differences in implementation and structure, not fundamental function. All of the capabilities of Mantle — and DirectX 12 — are also built into Vulkan.

As far as gaming support, Mantle will continue to be baked into games like Star Citizen and Battlefield Hardline — AMD signed an agreement for comprehensive support in Frostbite 3, and as far as we know that agreement will continue to be honored. Going forward, AMD has said that Mantle will be used to serve AMD as a graphics innovation platform “available to select partners with custom needs.”

All announced titles, including games like Star Citizen and BF: Hardline, will support Mantle

One of those needs is almost certainly tied to the Liquid VR project that AMD announced and discussed yesterday at GDC. While the company’s presentation didn’t formally mention Mantle, one of the topics discussed is how AMD wants to use a GPU to drive the VR simulation for each eye.

This kind of capability is only possible if your GPUs can keep discrete datasets in memory, rather than duplicating all data across both GPUs. That kind of asynchronous compute is only possible outside the conventional DirectX 11 API.

AMD believes that better GPU programming can address some of the juddering and update problems that still hurt current VR headsets. Again, the company hasn’t formally confirmed that it’s using Mantle for these efforts. But it would make sense for AMD to use its own API to drive the creation of new rendering methods — it can expand and extend Mantle in ways that it can’t change either Vulkan or Direct3D (at least not without a lengthy submission and ratification process).

Solar Impulse 2 gears up for round-the-world solar-powered flight

A team of Swiss engineers, aviation experts, and designers is finishing final preparations to launch Solar Impulse 2, a solar-powered plane with a wingspan larger than a Boeing 747. When Solar Impulse 2 gets airborne next week, it will begin a historic trip around the world. If all goes to plan, this will be the first aircraft to circumnavigate the globe powered entirely by the sun.

The Solar Impulse 2 has a huge wingspan, but the carbon fiber body of the plane is quite narrow. There’s only space for a single person (the pilot), and it doesn’t sound particularly comfortable. The design dedicates only 3.8 cubic meters of space for the pilot, which is just enough for the reclining multipurpose seat. It’s a chair, bed, and even a toilet. The cabin is also unheated and unpressurized, so the pilot will need to rely on oxygen canisters and thermal insulation in the cockpit structure.

Solar Impulse 2 will be piloted by the organization’s co-founders Bertrand Piccard and André Borschberg. They’ll take turns being crammed into this unpleasant little space for several days at a time, including one five day stretch over the Pacific Ocean. The round-the-world trip is being made in 12 legs over the course of several months, so the pilots will have the chance to trade places after each layover. This also gives the Solar Impulse team a chance to make sure the plane is still in proper working order. Even with years of testing, there’s a lot that can go wrong.

Solar Impulse 2 has 17,248 solar panels covering the wings, which can soak in enough power during the day to keep the four propellers going all night. Power will be stored in the craft’s lithium-ion batteries for use at that time as well. The batteries take up about a quarter of Solar Impulse 2’s 5,000-pound heft. That’s about the same as a midsize sedan, which is light for a plane and good for overall efficiency. Solar Impulse 2 can reach speeds of nearly 100 mph, but the plan is to limit speed to about 60 mph to get a little more distance out of the batteries.

The team arrived in Abu Dhabi, United Arab Emirates two months ago to conduct the final tests of Solar Impulse 2 before beginning the real flight. The plane has been taken on several multi-hour test flights in Abu Dhabi, and the pilots report no issues. The test flights were less than 250 miles, though. Several of the legs will be a few thousand miles, but Piccard and Borschberg are confident the plane will perform well.

Takeoff is currently scheduled for Monday March 9th. That first leg will be a short one, just a few hundred miles to Oman. Future legs will be longer with stops in Nanjing, Hawaii, New York, North Africa, and more. It would be more impressive if the plane managed the trip in one go, but this is still a huge technical achievement. Future solar aircraft might not need checkups every few thousand miles, but humans will still like to get out and stretch their legs.