Introduction

XFX Radeon RX 7800 XT MERC 319 review
With 16GB and a proper amount of raw shader performance at $539

For a while now, rumours have been flooding the graphics card arena, and as so often, most of them become an actuality. Meet the new Navi 32-based GPU models. The Radeon 7800 XT with its 16GB 256-bit memory configuration at 19.5 Gbps, is bound to impress. This particular iteration is poised to utilize the complete 60 CU / 3840 Shader processors setup of the GPU and boasts a Total Board Power (TBP) of 263W. The AMD Radeon RX 7800 XT GPU is built upon the Navi 32 SKU framework and thus chiplets, incorporating four Memory Controller Domains (MCDs). The GPU core boasts 3840 cores, meticulously distributed across 60 Compute Units to enhance performance. Additionally, the GPU incorporates a substantial 64 MB Infinity Cache, functioning at an 18 Gbps pin speed, yielding a commendable total bandwidth of 576 GB/s. The second Navi 32 variant, aka Radeon RX 7700 XT, sees a friendly 54 CU/3456 shader processor configuration, complemented by 12GB memory on a 192-bit bus running at an effective 18 Gbps data rate. This points towards a Navi 32 iteration with one of the four MCDs disabled, resulting in 48 MB of Infinity Cache. The core setup of the RX 7700 XT is anticipated to encompass approximately 54 Compute Units, housing a total of 3456 stream processors.

The XFX graphics card boasts a TGP of 236W and operates at a boost speed of 2565 MHz. A notable feature is its innovative two-phase vacuum heat transfer system, which offers superior heat dissipation compared to conventional cold plate techniques. At the heart of this card lies a nickel-plated copper core, incorporating a vapor chamber. This component adeptly pulls heat away from the GPU, redirecting it through six 6mm heatpipes for optimal thermal conductivity.

The card's cooling system comprises three fans: two 100mm fans with 96mm blades and a central 90mm fan fitted with 86mm blades. Collectively, they facilitate premium airflow across the card. Impressively, the fans suspend operations when the card's temperature drops below 50°C, ensuring energy efficiency. The fan speed is regulated by various thermal indicators, including the GPU's junction temperature, a set fan RPM benchmark of 1600 RPM, and the memory temperature. When in use, the fan maintains the preset RPM until either the GPU Junction or Memory temperature threshold is reached. It then adjusts its velocity to sustain the designated temperatures.

The card's die-cast aluminum backplate has a twofold purpose: it provides protection while doubling as an auxiliary heatsink. To enhance heat dispersion, thermal pads are strategically positioned on the PCB's rear, channeling heat towards the backplate. Enhancing its cooling capability, the backplate is designed with ridges to augment its surface area, thus amplifying thermal efficiency. In essence, this XFX card distinctively deviates from the standard reference design.