Introduction

Gainward GeForce RTX 5080 Phoenix GS is the company's value custom-design take on the NVIDIA GeForce RTX 5080. The Phoenix line of graphics cards strike a balance, featuring a factory overclock, low noise, and are generally priced closer to the NVIDIA MSRP, while the company's Phantom line of graphics cards take the upper crust in product design and performance. The Phoenix series is best for those looking for an RTX 5080 that they can install and get gaming. There are still plenty of premium touches, such as a vapor chamber-based cooling solution, dual-BIOS, double ball-bearing fans, and a touch of RGB LED lighting. The card also offers a fairly high factory overclock that can level up to some premium custom designs from other brands.



The GeForce RTX 5080 is designed to serve the same gaming use-case as the RTX 5090, which we reviewed last week. It enables you to enjoy today's AAA games at 4K Ultra HD resolution with maximum settings and ray tracing enabled. While the RTX 5090 caters to broader markets, including AI development and compute thanks to its lavish 32 GB memory over a 512-bit memory bus, the RTX 5080 is squarely aimed at gamers seeking top-tier performance. Its starting price is precisely half that of the RTX 5090, and when you examine its specifications, you'll notice that many figures are either approximately or exactly half of what appears on the RTX 5090 spec sheet.

The RTX 5080 is based on the GB203 silicon, which is NVIDIA's second-largest chip to implement the GeForce Blackwell graphics architecture. This lean piece of silicon is built on the exact same NVIDIA 4N foundry node at TSMC, which is derived from its 5 nm EUV process. The RTX 5080 maxes out the GB203 enabling all 84 streaming multiprocessors (SM) present on the silicon. This yields 10,752 CUDA cores, 336 Tensor cores, 84 RT cores, 336 TMUs, and 112 ROPs. It also features all 64 MB of the on-die L2 cache, and two sets of NVDEC and NVENC video accelerators that support 4:2:2 formats for AV1 and HEVC. The chip features a 256-bit wide GDDR7 memory bus, which drives 16 GB of memory. NVIDIA is running this memory at 30 Gbps on the RTX 5080, yielding 960 GB/s of bandwidth—a 34% increase over that of the RTX 4080.

The GeForce Blackwell graphics architecture debuts a revolutionary new concept called Neural Rendering. The easiest way to describe this would be to use a generative AI model to create objects, materials, and textures that are then combined with a conventionally rendered raster 3D scene, just like RTX combines ray traced objects to it. This is exclusive to Blackwell because the chip has the capability to accelerate large AI models and render 3D graphics concurrently, with fine-grained performance control, thanks to a new on-die hardware scheduler called AI management processor (AMP). The new Blackwell SM has all the silicon-level groundwork for neural rendering, and NVIDIA even worked with Microsoft to standardize this at an API level, letting 3D applications directly address Tensor cores. The new 4th Gen RT core comes with hardware acceleration for Mega Geometry, the ability to give ray traced objects exponentially higher poly counts.

The Gainward RTX 5080 Phoenix GS comes with a fairly hefty aluminium fin-stack cooling solution which uses a trio of large fans to push air through the heatsink. Airflow from the third fan goes through the heatsink and out the back of the card through a large cutout in the backplate. The new Cyclone Series fan from Gainward features wedged fan impeller blades that work to increase airflow. Gainward has given the RTX 5080 Phoenix GS a factory overclock of 2700 MHz boost (compared to 2617 MHz reference), while leaving the memory speed untouched. We couldn't get a price point from Gainward, we're expecting that the card will hit $1150.

NVIDIA Blackwell Architecture

NVIDIA does not provide a block diagram for the GB203 GPU (we asked), so we had to quickly hack one out from the GB202 diagram. This is accurate just not as pretty.

The GeForce Blackwell graphics architecture heralds NVIDIA's 4th generation of RTX, the late-2010s re-invention of the modern GPU that sees a fusion of real time ray traced objects with conventional raster 3D graphics. With Blackwell, NVIDIA is helping add another dimension, neural rendering, the ability for the GPU to leverage a generative AI to create portions of a frame. This is different from DLSS, where an AI model is used to reconstruct details in an upscaled frame based on its training date, temporal frames, and motion vectors. Today we are reviewing NVIDIA's second-biggest silicon from this generation, the RTX 5080. At the heart of this graphics card is the new 5 nm GB203 silicon. This chip has very similar die size and transistor counts to the previous generation AD103 powering the RTX 4080, because both chips are built on the exact same process—TSMC's "NVIDIA 4N", or 5 nm EUV with NVIDIA-specific characteristics—but is based on the newer Blackwell graphics architecture. The GB203 measures 378 mm² in die-area and rocks 45.6 billion transistors (compared to the 378.6 mm² die-area and 45.9 billion transistors of the AD103). This is where the similarities end.

The GB203 silicon is laid out essentially in the same component hierarchy as past generations of NVIDIA GPUs, but with a few notable changes. The GPU features a PCI-Express 5.0 x16 host interface. PCIe Gen 5 has been around since Intel's 12th Gen Core "Alder Lake" and AMD's Ryzen 7000 "Zen 4," so there is a sizable install-base of systems that can take advantage of it. The GPU is of course compatible with older generations of PCIe. The GB203 also features the new GDDR7 memory interface that's making its debut with this generation. The chip features a 256-bit wide memory bus, which is half the bus width of the GB202 powering the RTX 5090. NVIDIA is using this to drive 16 GB of memory at 30 Gbps speeds, yielding 960 GB/s of memory bandwidth, which is a 34% increase over the RTX 4080 and its 22.5 Gbps GDDR6X.

The GigaThread Engine is the main graphics rendering workload allocation logic on the GB203, but there's a new addition, a dedicated serial processor for managing all AI acceleration resources on the GPU, NVIDIA calls this AMP (AI management processor). Other components at the global level are the Optical Flow Processor, a component involved in older versions of DLSS frame generation and for video encoding; and an updated media acceleration engine consisting of two NVENC encode accelerators, and two NVDEC decode accelerators. The new 9th Gen NVENC video encode accelerators come with 4:2:2 AV1 and HEVC encoding support. The central region of the GPU has the single largest common component, the 64 MB L2 cache, which the RTX 5080 maxes out.


Each graphics processing cluster (GPC) is a subdivision of the GPU with nearly all components needed for graphics rendering. On the GB203, a GPC consists of 12 streaming multiprocessors (SM) across 6 texture processing clusters (TPCs), and a raster engine consisting of 16 ROPs. Each SM contains 128 CUDA cores. Unlike the Ada generation SM that each had 64 FP32+INT32 and 64 purely-FP32 SIMD units, the new Blackwell generation SM features concurrent FP32+INT32 capability on all 128 SIMD units. These 128 CUDA cores are arranged in four slices, each with a register file, a level-0 instruction cache, a warp scheduler, two sets of load-store units, and a special function unit (SFU) handling some special math functions such as trigonometry, exponents, logarithms, reciprocals, and square-root. The four slices share a 128 KB L1 data cache, and four TMUs. The most exotic components of the Blackwell SM are the four 5th Gen Tensor cores, and a 4th Gen RT core.


Perhaps the biggest change to the way the SM handles work introduced with Blackwell is the concept of neural shaders—treating portions of the graphics rendering workload done by a generative AI model as shaders. Microsoft has laid the groundwork for standardization of neural shaders with its Cooperative Vectors API, in the latest update to DirectX 12. The Tensor cores are now accessible for workloads through neural shaders, and the shader execution reordering (SER) engine of the Blackwell SM is able to more accurately reorder workloads for the CUDA cores and the Tensor core in an SM.


The new 5th Gen Tensor core introduces support for FP4 data format (1/8 precision) to fast moving atomic workloads, providing 32 times the throughput of the very first Tensor core introduced with the Volta architecture. Over the generations, AI models leveraged lesser precision data formats, and sparsity, to improve performance. The AI management processor (AMP) is what enables simultaneous AI and graphics workloads at the highest levels of the GPU, so it could be simultaneously rendering real time graphics for a game, while running an LLM, without either affecting the performance of the other. AMP is a specialized hardware scheduler for all the AI acceleration resources on the silicon. This plays a crucial role for DLSS 4 multi-frame generation to work.


The 4th Gen RT core not just offers a generational increase in ray testing and ray intersection performance, which lowers the performance cost of enabling path tracing and ray traced effects; but also offers a potential generational leap in performance with the introduction of Mega Geometry. This allows for ray traced objects with extremely high polygon counts, increasing their detail. Poly count and ray tracing present linear increases in performance costs, as each triangle has to intersect with a ray, and there should be sufficient rays to intersect with each of them. This is achieved by adopting clusters of triangles in an object as first-class primitives, and cluster-level acceleration structures. The new RT cores introduce a component called a triangle cluster intersection engine, designed specifically for handling mega geometry. The integration of a triangle cluster compression format and a lossless decompression engine allows for more efficient processing of complex geometry.


The GB203 and the rest of the GeForce Blackwell GPU family is built on the exact same TSMC "NVIDIA 4N" foundry node, which is actually 5 nm, as previous-generation Ada, so NVIDIA directed efforts to finding innovative new ways to manage power and thermals. This is done through a re-architected power management engine that relies on clock gating, power gating, and rail gating of the individual GPCs and other top-level components. It also worked on the speed at which the GPU makes power-related decisions.


The quickest way to drop power is by adjusting the GPU clock speed, and with Blackwell, NVIDIA introduced a means for rapid clock adjustments at the SM-level.


NVIDIA updated both the display engine and the media engine of Blackwell over the previous generation Ada, which drew some flack for holding on to older display I/O standards such as DisplayPort 1.4, while AMD and Intel had moved on to DisplayPort 2.1. The good news is that Blackwell supports DP 2.1 with UHBR20, enabling 8K 60 Hz with a single cable. The company also updated NVDEC and NVENC, which now support AV1 UHQ, double the H.264 decode performance, MV-HEVC, and 4:2:2 formats.

Neural Rendering

Neural Rendering promises to be as transformative to modern graphics as programmable shaders itself. 3D Graphics rendering evolved from fixed-function over the turn of the century, to programmable shaders, HLSL, geometry shaders, compute shaders, and ray tracing, over the past couple of decades. In 2025, NVIDIA is writing the next chapter in this journey with Blackwell neural shaders. This allows for a host of neural-driven effects, including neural materials, neural volumes, and even neural radiance fields. Microsoft introduced the new Cooperative Vectors API for DirectX in a recent update, making it possible to access Tensor cores within a graphics API. Combined with a new shading language, Slang, this breakthrough enables developers to integrate neural techniques directly into their workflows, potentially replacing parts of the traditional graphics pipeline. Slang splits large, complex functions into smaller pieces that are easier to handle. Given that this is a DirectX standard API feature, there is nothing that stops AMD and Intel from integrating Neural Rendering (Cooperative Vectors) into their graphics drivers.

RTX Neural Materials works to significantly reduce the memory footprint of materials in 3D scenes. Under conventional rendering, the memory footprint of a material is bloated from complex shader code. Neural materials convert shader code and texture layers into a compressed neural representation. This results in up to a 7:1 compression ratio and enables small neural networks to generate stunning, film-like materials in real-time. For example, silk rendered with traditional shaders might lack the multicolored sheen seen in real life. Neural materials, however, capture intricate details like color variation and reflections, bringing such surfaces to life with unparalleled realism—and at a fraction of the memory cost.


The new Neural Radiance Cache, which dynamically trains a neural network during gameplay using the user's GPU, allowing light transport to be cached spatially, enabling near-infinite light bounces in a scene. This results in realistic indirect lighting and shadows with minimal performance impact. NRC partially traces 1 or 2 rays before storing them in a radiance cache, and infers an infinite amount of rays and bounces for a more accurate representation of indirect lighting in the game scene.

DLSS 4 and Multi Frame Generation

DLSS 4 introduces a major leap in image quality and performance. It isn't just a version bump with the introduction of a new feature, namely Multi Frame Generation, but introduces updates to nearly all DLSS sub-features. DLSS from its very beginning relied on AI to reconstruct details in super resolution, and with DLSS 4, NVIDIA is introducing a new transformer-based AI model to succeed the convolutional neural networks previous used, for double the parameters, four times the compute performance, and significantly improved image quality. Ray Reconstruction, introduced with DLSS 3.5, gets a significant image quality update with the new transformer-based model.


To understand Multi Frame Generation, you need to understand how DLSS Frame Generation, introduced with GeForce Ada, works. An Optical Flow Accelerator component gives the DLSS algorithm data to generate an entire frame using a neural network, using information from a previous rendered frame, effectively doubling frame rate. In Multi Frame Generation, AI takes over the functions of optical flow, to predict up to three frames following a conventionally rendered frame, effectively drawing four frames form the rendering effort of one.


Now, assuming this rendered frame is a product of Super Resolution, with the maximum performance setting generating 4x the pixels from a single rendered pixel, you're looking at a possibility where the rendering effort of 1/4th a frame goes into drawing 4 frames, or 15 in every 16 pixels being generated entirely by DLSS. When generating so many frames, Frame Pacing becomes a problem—irregular frame intervals impact smoothness. DLSS 4 addresses these issues by using a dedicated hardware unit inside Blackwell, which takes care of flip metering, reducing frame display variability by 5-10x. The Display Engine of Blackwell contains the hardware for flip metering.

NVIDIA Reflex 2

The original NVIDIA Reflex brought about a significant improvement to the responsiveness of maxed out graphics in competitive online gameplay, by compacting the rendering queue with the goal of reducing the whole system latency by up to 50%. Reflex is mandatory in DLSS 3 Frame Generation, given the latency cost imposed by the technology. Multi-frame generation calls for an equally savvy piece of technology, so we hence have Reflex 2. NVIDIA claims to have achieved a 75% reduction in latency with Frame Warp, which updates the camera (viewport) positions based on user inputs in real-time, and then uses temporal information to reconstruct the frame to display.

Packaging

The Card

Gainward's Phoenix GS uses a mostly-black design with a silvery metal highlight element along the top edge. On the back you get a metal backplate with a large cutout.


Dimensions of the card are 33.0 x 13.0 cm, and it weighs 1595 g.


Installation requires three slots in your system. We measured the card's width to be 60 mm.


Display connectivity includes three standard DisplayPort 2.1b and one HDMI 2.1b.

Standard for all GeForce RTX 50-series Blackwell cards is a new display engine that supports three DisplayPort 2.1b outputs, each capable of UHBR20; and one HDMI 2.1a. Both interfaces support DSC (display stream compression). With DSC enabled, a single DisplayPort on this card can drive 4K 12-bit HDR at 480 Hz; or 8K 12-bit HDR at up to 165 Hz. The RTX 5080 features an updated media acceleration engine with support for 4:2:2 video formats, AV1 UHQ, and MV-HEVC. There are two independent NVENC and NVDEC units.


The card uses a single 16-pin connector, which allows a maximum power draw of 600 W.


Gainward has added an RGB illumination zone on the "Phoenix" logo.


The BIOS switch lets you select between the default "Performance" BIOS and a secondary "quiet" BIOS, which runs the fans at lower speeds.