Software-Accelerated vs Hardware-Accelerated: Ray Tracing Basics

Software-Accelerated vs Hardware-Accelerated: Ray Tracing Basics

There are two general routes for implementing ray tracing. This is through either software or hardware. Take note that ray tracing is a rendering technique that simulates the behavior of light and its interactions with objects in the scene. Software-accelerated ray tracing does this using a software program designed to perform ray tracing calculations and graphics rendering using available hardware or processors while hardware-accelerated ray tracing does the same using a dedicated hardware component such as a graphics processor or ray tracing cores.

Understanding the Difference Between Software-Accelerated Ray Tracing and Hardware-Accelerated Ray Tracing

Software-accelerated ray tracing is a decades-old technology that has been used in filmmaking and animation to render three-dimensional scenes that simulate the path of light and its lifelike interactions with scenic elements. It is still important to note that rendering via this route is a post-product process. It cannot be implemented in real time.

The introduction of hardware-accelerated ray tracing has enabled faster and more efficient rendering. It has also enabled real-time ray tracing which is useful in situations or applications in which real-time rendering is critical. Notable examples include video gaming and rendering of virtual reality, augmented reality, or mixed reality environments.

Below are details comparing and explaining further the difference between software-accelerated ray tracing and hardware-accelerated ray tracing:

1. Software-Accelerated Ray Tracing

• Processing: The process of performing ray tracing calculations is done using the general-purpose cores of a central processing unit or other relevant processors such as a graphics processing unit or a field-programmable gate array.

• Performance: A notable disadvantage of software-accelerated ray tracing is that it tends to be slower and less efficient compared to hardware-accelerated ray tracing. It is also not ideal for real-time ray tracing. The CPU or other processor is not optimized for the parallel processing requirement of ray tracing algorithms.

• Requirements: This is still considered more versatile because it can use existing hardware resources and even older or less powerful computer systems. This also means that it is more accessible to resource-strapped users.

2. Hardware-Accelerated Ray Tracing

• Processing: The process involved in ray tracing calculations is done using specialized hardware such as a dedicated GPU or its specific ray tracing cores. The hardware component is optimized for the required mathematical calculations.

• Performance: A notable advantage of hardware-accelerated ray tracing is that it is significantly faster and more efficient. This allows real-time ray tracing for rendering video game graphics and other applications. The downside is that the needed hardware adds to the overall cost of the entire computer system.

• Requirements: This is a more expensive and less accessible option because GPUs optimized for ray tracing tend to be more expensive than GPUs without these capabilities. Take note that real-time ray tracing is computationally taxing.

It is worth reiterating the fact that the software-based route for ray tracing is more versatile but computationally slower and less efficient. The hardware-dependent route leverages the advantages of parallel processing to deliver faster mathematical calculations and even enable real-time ray tracing calculations and graphics rendering.

The choice between the two depends on the specific requirements and performance goals of a particular application. The arrival of discrete GPUs with ray tracing capabilities is starting to make this rendering technique more common. Even mobile system-on-chips with integrated GPUs have now included native hardware capabilities for ray tracing.

Quadro RTX from Nvidia was the first consumer-grade discrete GPU with real-time ray tracing. It was introduced in 2018 and has since been included in other GeForce RTX GPUs. AMD has also included a similar feature in its mid-range to high-end graphics processors under the Radeon RX GPU line while Intel has introduced it in its Intel Arc GPUs.

The Samsung Exynos 2200 and MediaTek Dimensity which were introduced in 2022 were the first mobile chips to have integrated GPUs with hardware-accelerated ray tracing. Apple introduced the flagship iPhone 15 Pro in 2023 with ray tracing via its A17 Pro chip while Qualcomm has followed suit with its Snapdragon 8 Gen 2.