Apple first introduced Metal in June 2014 as one of the features of the iPhone 5S, iPad Air, and iPad Mini, and their Apple A7 system-on-a-chip. It has since become a staple feature of succeeding iPhone and iPad devices and has also been part of Mac devices since June 2015. The main reason behind its development is to maximize the full potential of Apple-designed hardware and to both control and optimize the entire hardware and software stack for iOS and macOS devices.
Everything You Need to Know About Metal: A Standard Application Programming Interface for Graphics and Compute from Apple
Advantages of Metal API: Purpose and Applications
Metal is an application programming interface or API. This means that it is an interface between an app and a specific hardware component like an integrated graphics processing unit. Apple designed Metal as a standard graphics and compute API for iOS and macOS devices because existing and equivalent APIs like OpenGL and OpenCL were not optimized to run on Apple hardware and have the potential to cause performance bottlenecks. Below are the advantages of Metal and its specific purpose and applications:
1. Grants Low-Level GPU Access
The main purpose of Metal and one of the advantages of integrating it into Apple products is that it grants developers direct access to the graphics processing units. This access enables finer control and better performance compared to high-level APIs like OpenGL. Developers can tell the graphics processor exactly what to do in a step-by-step fashion. Furthermore, considering the chip strategy of Apple, this maximizes the potential of the integrated graphics processors found in the Apple A and Apple M series of systems-on-chips.
2. Combines OpenGL and OpenCL
It is also worth reiterating the fact that it is both a graphics and compute application programming interface. Another one of the advantages of Metal is that it combines the features of OpenGL and OpenCL into a single and unified interface. This simplifies the development of certain tasks. However, because OpenGL and OpenCL are high-level APIs that serve as pre-made building blocks, they provide limited options. Apple developed Metal with fine-tuning in mind. Remember that it grants developers access to the graphics processors.
3. Overall Performance Improvement
This API leverages the hardware capabilities of integrated GPUs and lowers the CPU workload for tasks like graphics rendering, processing data, and running artificial intelligence models. It provides compute shaders for general-purpose compute kernels that run on GPU and supports tessellation shaders for generating complex geometry on the GPU. Other specific shader functions include neural network processing, ray tracing, and advanced math operations. Hence, based on these, hardware acceleration is another advantage of Metal.
4. Extensive and Specific Applications
One of the main applications of Metal is in developing video games for iOS or iPadOS and macOS. This API is also integrated into visionOS devices or the Apple Vision Pro. It helps in rendering the mixed reality or producing the spatial computing user interface of the headset. Popular game engines such as Unreal Engine and Unity support this API. Productivity apps such as Final Cut Pro use this API to accelerate effects and video processing. Metal can also be used to access and leverage the parallel processing capabilities of Apple chips.
Disadvantages of Metal API: Issues and Limitations
The integration of Metal in products like the iPhone, iPad, and Mac is also part of the infamous attempt of Apple to maintain control over its product ecosystem. Remember that it is an Apple standard. This does not sit well with all software and video game developers. Some have noted that using this API locks them into the Apple ecosystem and leaves them with fewer capabilities to port software or apps to other platforms. The developer community and resources are also limited. Below are the specific disadvantages of Metal API:
1. Platform-Specific Limitations
Remember that this API is the standard graphics and compute API for Apple devices such as iPhones and Mac computers. This is a problem for some developers because it increases the potential for vendor lock-in and also adds another layer of complexity to the workflow of cross-platform development. Note that developers need to use other APIs for non-Apple operating systems and devices or would need to make significant code changes and optimizations when porting a game or app from other platforms to Apple.
2. Has a Steeper Learning Curve
Another disadvantage of Metal is that it requires more knowledge and effort to utilize. Remember that it is a low-level graphics and compute API that provides developers with deeper control. This also comes with a more complex workflow. For example, in terms of resource management, it requires developers to manually handle this, unlike in high-level alternatives. It also requires them to write their own shaders in Metal Shading Language. Adding to these is the fact that it is an Apple standard that is inapplicable to other platforms.
3. Advantages From Alternatives
It is also important to underscore the fact that developing games or apps using Metal is not always necessary. Those who are pursuing simpler projects or are targeting a particular platform are better off using other graphics or computer application programming interfaces. OpenGL and OpenCL are higher-level APIs that are more practical because of their easier learning curve and wider platform support. Vulkan is a low-level graphics and compute API for Linux and Android while DirectX or Direct3D is an API for Windows and Xbox platforms.
4. No Support for Older Apple Devices
Remember that Apple launched Metal in 2014 and it has been supported in Apple devices that feature chips starting from the Apple A7. This means that older iPhones or iPads like the iPhone 5 or fourth-generation iPad cannot run games and apps that are based on this graphics and compute API. Furthermore, considering that Apple now uses its own chips for newer generations of Mac computers, this API also works best in Apple M chips. It still supports other hardware such as Intel UHD 630 and the AMD Graphics Series 500 and 600.
