Introduction

XFX sprung a surprise along the sidelines of the 2024 Computex with their innovative new Radeon RX 7900 XTX Mercury Magnetic Air. This custom-design graphics card powered by AMD's flagship GPU is a step up from the company's top Merc 310 product. It started life out as the China-exclusive RX 7900 XTX Phoenix Nirvana, before the company decided to give the card a worldwide launch as the RX 7900 XTX Magnetic Air. Behind the name is an XFX innovation with the card's fan design. You might see the name "MagAir" or "Mag Air" in some places and stores, but XFX decided to change the name of the product to "Magnetic Air" a few days ago.

Several graphics card manufacturers are beginning to see the value in making the fans of their cooling solutions easily replaceable by end-users, with minimal need for disassembly. This is to let users clean the fans, for consistent cooling performance. The way they usually go about doing this is by making it straightforward to take off the cooler shroud without disturbing the heatsink underneath. Other companies make it easy to unscrew the fans off their cavities from the cooler shroud, but this needs a screwdriver to access three screws from between the fan blades, making you run the risk of bending or breaking the blades, which could imbalance the fan and damage its bearing down the line. XFX took a novel approach to this problem. The fans can be simply pulled off like fridge magnets, with no tools needed!



Each of the three fans on the XFX RX 7900 XTX Mercury Magnetic Air comes with magnetized grooves behind the hub that interlock with grooves on the cooler shroud, and secured in place by magnetism that's strong enough to hold the fan in place even at its highest RPM. This magnetism, however, is weak enough that a user can pull the fan off without bending or deforming the impeller in the process. There are no wires involved, the grooves have contact points for the four pins of the fan that include power, PWM signal, and speed sensor. There's more to this card than its innovative fan design. The aluminium fin-stack heatsink is improved over the XFX RX 7900 XTX Merc 310. The designs of the cooler shroud and backplate expose a lot more of the heatsink along the top- and bottom edges, improving exhaust ventilation.

AMD Radeon RX 7900 XTX is the company's flagship GPU, designed for maxed out gameplay at 4K Ultra HD, including with ray tracing. It's the most scaled out implementation of the RDNA 3 graphics architecture, which seeks to introduce generational performance and efficiency uplifts riding on the 5 nm foundry node; AI acceleration on the GPU, and a second generation implementation of AMD's ray tracing hardware pipeline that improves ray intersection performance by 50%. The new multi-draw indirect accelerator (MDIA) can significantly improve performance of DirectX 12 applications that use the multi-draw indirect instruction.

The RDNA 3 compute unit design offers a 17% generational performance uplift and support for newer math formats. This uplift, coupled with increased engine clocks, memory bandwidth, and an overall increase in the compute unit count, translates to a 50% shader performance uplift over the previous generation RX 6900 XT. AMD has increased the memory size to 24 GB, and widened the memory bus to 384-bit, besides running the memory at a higher 20 Gbps speed, for a massive 87% increase in memory bandwidth which allowed for a generational reduction of the Infinity Cache size to 96 MB, down from 128 MB.

The Radeon RX 7900 XTX is based on "Navi 31," which is the first gaming GPU to use a chiplet architecture. AMD identified all the logic-heavy components that benefit from the switch to 5 nm from 7 nm, and clumped them into a large central chiplet called the graphics compute die (GCD) built on 5 nm, while the other components that don't benefit as much from the switch, namely the Infinity Cache and the memory controllers, are disaggregated into six small chiplets called memory cache dies (MCDs), built on the 6 nm node. Each MCD has a 16 MB segment of the Infinity Cache, and a 64-bit portion of the 384-bit memory bus.

The RX 7900 XTX maxes out the "Navi 31" GPU, enabling all 96 compute units, and all 6 MCDs. You hence have 6,144 stream processors, 96 Ray accelerators, 192 AI accelerators; 384 TMUs, and a staggering 192 ROPs. The GPU's frontend runs at a higher frequency than the shader engines. AMD has given the RX 7900 XTX a Game clock of 2365 MHz, and 2498 MHz boost clock. The memory, as we mentioned, ticks at 20 Gbps, yielding 960 GB/s of memory bandwidth. XFX has overlocked the GPU to 2482 MHz Game clock, and 2615 MHz boost. The card features a dual-BIOS, with the default OC BIOS enabling these clocks and the second BIOS increasing the power limit a bit above stock. Another novelty is that the thermal paste used is Honeywell PTM7950, a phase change material that should provide superior performance and longevity over typical pastes. XFX is pricing the Radeon RX 7900 XTX Mercury Magnetic Air at $980.