Khronos Announces OpenCL 2.1: C++ Comes to OpenCL

Alongside today’s announcements of Vulkan and SPIR-V, Khronos is also using the occasion of the 2015 Game Developers Conference to announce the next iteration of OpenCL, OpenCL 2.1.

OpenCL 2.1 marks two important milestones for OpenCl. First …

AMD Lays Out Future of Mantle: Changing Direction In Face of DX12 and glNext

Much has been made over the advent of low-level graphics APIs over the last year, with APIs based on this concept having sprouted up on a number of platforms in a very short period of time. For game developers this has changed the API landscape dramatically in the last couple of years, and it’s no surprise that as a result API news has been centered on the annual Game Developers Conference. With the 2015 conference taking place this week, we’re going to hear a lot more about it in the run-up to the release of DirectX 12 and other APIs.

Kicking things off this week is AMD, who is going first with an update on Mantle, their in-house low-level API. The first announced of the low-level APIs and so far limited to AMD’s GCN’s architecture, there has been quite a bit of pondering over the future of the API in light of the more recent developments of DirectX 12 and glNext. AMD in turn is seeking to answer these questions first, before Microsoft and Khronos take the stage later this week for their own announcements.

In a news post on AMD’s gaming website, AMD has announced that due to the progress on DX12 and glNext, the company is changing direction on the API. The API will be sticking around, but AMD’s earlier plans have partially changed. As originally planned, AMD is transitioning Mantle application development from a closed beta to a (quasi) released product – via the release of a programming guide and API reference this month – however AMD’s broader plans to also release a Mantle SDK to allow full access, particularly allowing iit to be implemented on other hardware, has been shelved. In place of that AMD is refocusing Mantle on being a “graphics innovation platform” to develop new technologies.

As far as “Mantle 1.0” is concerned, AMD is acknowledging at this point that Mantle’s greatest benefits – reduced CPU usage due to low-level command buffer submission – is something that DX12 and glNext can do just as well, negating the need for Mantle in this context.  For AMD this is still something of a win because it has led to Microsoft and Khronos implementing the core ideas of Mantle in the first place, but it also means that Mantle would be relegated to a third wheel. As a result AMD is shifting focus, and advising developers looking to tap Mantle for its draw call benefits (and other features also found in DX12/glNext) to just use those forthcoming APIs instead.

Mantle’s new focus in turn is going to be a testbed for future graphics API development.  Along with releasing the specifications for “Mantle 1.0”, AMD will essentially keep the closed beta program open for the continued development of Mantle, building it in conjunction with a limited number of partners in a fashion similar to how Mantle has been developed so far.

Thie biggest change here is that any plans to make Mantle open have been put on hold for the moment with the cancelation of the Mantle SDK. With Mantle going back into development and made redundant by DX12/glNext, AMD has canned what was from the start the hardest to develop/least likely to occur API feature, keeping it proprietary (at least for now) for future development. Which is not to say that AMD has given up on their “open” ideals entirely though, as the company is promising to deliver more information on their long-term plans for the API on the 5^th, including their future plans for openness.

Mantle Pipeline States

As for what happens from here, we will have to see what AMD announces later this week. AMD’s announcement is essentially in two parts: today’s disclosure on the status of Mantle, and a further announcement on the 5^th. It’s quite likely that AMD already has their future Mantle features in mind, and will want to discuss those after the DX12 and glNext disclosures.

Finally, from a consumer perspective Mantle won’t be going anywhere. Mantle remains in AMD’s drivers and Mantle applications continue to work, and for that matter there are still more Mantle enabled games to come (pretty much anything Frostbite, for a start). How many more games beyond 2015 though – basically anything post-DX12 – remains to be seen, as developers capable of targeting Mantle will almost certainly want to target DX12 as well as soon as it’s ready.

Update 03/03: To add some further context to AMD’s announcement, we have the announcement of Vulkan (aka glNext). In short Mantle is being used as a building block for Vulkan, making Vulkan a derivative of Mantle. So although Mantle proper goes back under wraps at AMD, “Mantle 1.0” continues on in an evolved form as Vulkan.

Imagination Announces PowerVR G6020 GPU & PowerVR Series 5 Video Encoder

With Mobile World Congress 2015 now in full swing, Imagination Technologies is taking to the show today to announce a couple of new additions to the PowerVR family of video products.

First off is a new low-end GPU in the PowerVR Series6XE family, the G6020. The G6020 is aimed at entry-level mobile devices, embedded computers, and high-end wearables, and is intended to be Imagination’s new entry-level Series6XE part.

From a design perspective, the G6020 is aimed at very simple desktop workloads – the Android UI, wearable interfaces, etc. Imagination has essentially built the bare minimum GPU needed to drive a 720p60 display, taking out any hardware not necessary to that goal such as compute and quite a bit of geometry throughput. What remains is enough of a ROP backend (pixel co-processor) to drive 720p, and the FP16 shading resources to go with it.

Meanwhile from a hardware perspective this is basically a significantly cut down 6XE part. G6020 drops to just a single 4 pipeline USC, versus the 8 pipeline USC found in the G6050, and 16 pipelines as found in a “complete” USC. The number of FP32 ALUs in each pipeline has also been reduced, going from the 6XE standard of 2 per pipeline to 1 for G6020, while the number of FP16 ALUs remains unchanged at 4. Along with scaling down the USCs, Imagination has also stripped down the G6020 in other ways, such as by taking out the compute data master.

The end result of their efforts is designed to be an incredibly small and incredibly low power OpenGL ES 3.0 GPU for devices that fall in the cheap/small range. G6020 is only 2.2mm2 in size on 28nm, making it similar in size to ARM’s Cortex-A7 CPU cores (a likely pairing target). And power consumption is low enough that it should be able to just fit into high-end wearables.

PowerVR Series 5 Video Encoder

Meanwhile Imagination’s second PowerVR announcement of the day is the announcement of their new PowerVR Series 5 family of video encoders.  This is Imagination’s entry into the HEVC (H.265) hardware encoder market, offering scalable designs for encoding H.264 and HEVC video.

In terms of designs Imagination will be offering 3 designs, the E5800, E5505, and E5300, targeted at progressively lower-end markets. The E5800 is the largest configuration and is aimed at the prosumer market, offering 4Kp60 encoding with 10-bit color and 4:2:2 chroma sampling (twice the sampling of standard 4:2:0 video). Below that is the E5505, the mainstream/premium mobile part with support for encoding up to 4Kp30, along with VP8 encoding and even MJPEG for certain legacy applications. Finally at the bottom of the list is the E5300, which is a small, low power encoder for 1080p30 applications (cameras/sensors/IoT and the like).

From a competitive standpoint, along with the expected synergy between the PowerVR encoders and PowerVR GPUs –support for directly handing off compressed memory, in particular – Imagination is also banking on being able to win a quality war with other mobile HEVC encoders.  By Imagination’s estimates they can offer equivalent quality at just 70% of the bitrate, which would give them a significant advantage. The company says that this is a result of having a newer encoder that is better tuned than competing encoders, and one that implements more HEVC features (e.g. 10-bit color), allowing them to achieve better compression and the resulting reduction in bitrates.

While Imagination’s testing methodology and resulting numbers to get here are open to interpretation – PSNR is important, though not the end-all of encoder measurements – HEVC encoders are still a fledgling field. There is still ample opportunity to improve on HEVC encoders and reach the same kind of highly tuned status that H.264 encoders have evolved to.

Wrapping things up, both new PowerVR products are now available for licensing.