Ray Tracing Explained for PC Buyers

What is ray tracing

Ray tracing is a rendering method that models how light interacts with objects in a scene. In traditional rasterization, the GPU processes geometry into pixels using approximations for shadows, reflections, and lighting. Ray tracing instead casts rays from the camera into the scene and calculates each ray's interactions with objects, materials, and light sources. This produces more physically accurate results: light reflects off shiny surfaces, refracts through glass, and casts soft shadows with realistic penumbra.

The technique has been used in film and architecture for years, but real-time ray tracing in games became practical only with dedicated hardware. The "RT" in GeForce RTX stands for Ray Tracing. NVIDIA introduced first-generation Ray Tracing Cores on the RTX 20 Series (Turing architecture), followed by second-generation on the RTX 30 Series (Ampere), third-generation on the RTX 40 Series (Ada Lovelace), and fourth-generation on the RTX 50 Series (Blackwell). Each generation increased the number of dedicated cores and their efficiency.

How RTX GPUs handle ray tracing: RT Cores

NVIDIA RTX graphics cards contain dedicated hardware called Ray Tracing Cores (RT Cores) that accelerate the ray-tracing pipeline. These cores handle bounding volume hierarchy (BVH) traversal and ray-triangle intersection calculations far faster than a general-purpose shader core could. The RTX 50 Series uses fourth-generation RT Cores, which NVIDIA states deliver up to 318 TFLOPS on the RTX 5090, 171 TFLOPS on the RTX 5080, 133 TFLOPS on the RTX 5070 Ti, 94 TFLOPS on the RTX 5070, 72 TFLOPS on the RTX 5060 Ti, 58 TFLOPS on the RTX 5060, and 40 TFLOPS on the RTX 5050.

These cores work alongside the GPU's Streaming Multiprocessors and Tensor Cores. When a game uses ray-traced effects, the RT Cores handle the geometry calculations, while the Tensor Cores run AI-based denoising and upscaling. The combination allows real-time ray tracing at playable frame rates a generation ago would have been impossible.

Performance cost of ray tracing and how DLSS helps

Enabling ray tracing in a game often cuts frame rates significantly, depending on the scene complexity and the number of ray-traced effects (shadows, reflections, global illumination, path tracing). This cost comes from the sheer number of ray calculations per frame: a single ray can spawn multiple bounces, each requiring intersection tests against the entire scene geometry.

To offset this performance hit, NVIDIA developed DLSS. DLSS uses dedicated Tensor Cores on RTX GPUs to reconstruct a high-resolution frame from a lower-resolution input. The RTX 50 Series supports DLSS 5, which includes Dynamic Multi Frame Generation that can generate up to five frames per traditionally rendered frame. NVIDIA describes DLSS as using "AI to infuse game scenes with lifelike lighting and materials." By rendering at a lower internal resolution and then upscaling, the GPU has more headroom for ray tracing calculations.

The practical takeaway: a desktop with an RTX 50 Series card can run ray tracing at high settings at 1440p or 4K resolutions when DLSS is enabled. Cards with higher RT TFLOPS ratings (like the RTX 5090 or RTX 5080) can handle heavier workloads like full path tracing, while lower-tier cards (RTX 5060, RTX 5050) can manage less demanding ray-traced effects at 1080p.

What to look for in a desktop for ray tracing

When choosing a prebuilt desktop for ray tracing, the most important component is the GPU. Look for a GeForce RTX card from the RTX 30, 40, or 50 Series. Higher-generation cards offer more efficient RT Cores and support newer DLSS versions. The RTX 50 Series also includes support for DLSS 3D-Guided Neural Rendering and Dynamic Multi Frame Generation, which can significantly improve ray traced performance.

The CPU and RAM should also be capable. Ray tracing calculations are GPU-bound, but the system must feed the GPU data fast enough. A modern multi-core processor and adequate RAM (16 GB or more) ensure the rest of the system does not become a bottleneck. For serious ray tracing workloads, consider a desktop with a high-tier RTX card and learn about DLSS technology.

For the best experience, target a desktop with at least 8 GB of VRAM for 1080p ray tracing, and more VRAM for higher resolutions. If you plan to use path tracing (a more intensive ray tracing technique), aim for the highest VRAM configuration available.

Which desktop is right for your ray tracing needs

To make the best choice, match the GPU tier to the resolution and quality you target. An RTX 5060 desktop handles ray tracing at 1080p with DLSS. An RTX 5070 Ti or RTX 5080 delivers strong 1440p ray tracing performance. For 4K path tracing, only the RTX 5090 provides enough RT TFLOPS. Browse the best prebuilt gaming PCs for the latest models and compare RTX 5080 desktops and RTX 5090 desktops for high-end builds.

What to pick for your use

Questions

What is ray tracing in simple terms?

Ray tracing is a way to create computer graphics that simulates how real light behaves. Instead of using shortcuts to fake lighting, it follows virtual rays of light from the camera to objects. This produces more realistic reflections, shadows, and lighting, but requires much more computing power.

Do I need a special GPU for ray tracing?

Yes. While some older games use ray tracing on the CPU, modern games require a GPU with dedicated hardware. NVIDIA GeForce RTX series cards have Ray Tracing Cores designed specifically for this task. Cards without these cores (like older GTX models) cannot run ray traced games at playable frame rates.

How much does ray tracing affect game performance?

Ray tracing can reduce frame rates significantly compared to traditional rasterization, depending on the scene and the number of ray-traced effects. Using DLSS can recover most of that performance by rendering at a lower resolution and using AI to upscale the image.

What is the difference between ray tracing and path tracing?

Path tracing is an advanced form of ray tracing that simulates millions of light paths per frame to achieve near-photorealistic results. It is much more computationally expensive than standard ray tracing, which typically uses a few specific effects like shadows or reflections.

Can I use ray tracing on an AMD Radeon GPU?

AMD Radeon RX 6000 and 7000 series GPUs also support ray tracing, but the implementation and performance vary. NVIDIA RTX cards generally have more mature driver support and wider game compatibility, and their Tensor Cores provide DLSS, which helps offset the performance cost.

Is ray tracing worth it for casual gaming?

It depends on your preferences. If you value visual fidelity and play games that offer extensive ray traced effects, it can dramatically improve immersion. If you play competitive titles where high frame rates matter most, you may prefer to disable ray tracing for maximum performance.

What role does DLSS play in ray tracing?

DLSS uses AI to upscale a lower-resolution image to a higher resolution, effectively reducing the GPU workload. When ray tracing is enabled, DLSS can restore lost frame rates, making ray traced gaming playable. The RTX 50 Series adds Dynamic Multi Frame Generation, which can generate up to five frames per rendered frame.

What is Mega Geometry in NVIDIA's fourth-gen RT Cores?

NVIDIA describes fourth-generation Ray Tracing Cores as "built for Mega Geometry," a technology that allows the GPU to handle larger, more detailed scenes with many objects. This enables more complex ray traced environments without severely impacting performance.