Introduction

Sapphire Radeon RX 7900 GRE Nitro+ is a premium custom design of AMD's performance segment graphics card that has eluded Western markets until now. The RX 7900 GRE (Golden Rabbit Edition) was originally conceived as a limited edition targeting the Chinese market, and was also available in Asian markets near China; but AMD has decided to give this a wider launch, if not a full global launch. It should be available in certain Western markets for purchase from tomorrow (February 27). This isn't a new GPU, with the earliest marketplace sightings of the card dating back to July 2023. Why then did AMD decide to give this card a wider launch now? This has to do with the January launch of NVIDIA's GeForce RTX 4070 Super and RTX 4070 Ti Super, which shook up the GPU market between $500 to $800.



The AMD Radeon RX 7800 XT launched at $550, with performance competitive to the then $600 RTX 4070, which caused its street price to trim down to around $580. The RTX 4070 Super convincingly beats the RX 7800 XT and displaces the RTX 4070 from its price, pushing it further down. This in turn forced the RX 7800 XT to settle around a $500 price point, creating a rather large gap between it and the RX 7900 XT. AMD already had the RX 7900 GRE carved up and selling on the Chinese market since July, so it was easy to just give it a wider launch.

AMD created the Radeon RX 7900 GRE by further cutting down the Navi 31 silicon which powers the RX 7900 XT and RX 7900 XTX. The company had created a smaller package substrate for the chip, so it could create RX 7900 series laptop GPUs with it. The smaller package helps in gaming notebooks where PCB real-estate is scarce. This package has a slimmer memory IO that's limited to 256-bit, and has fewer power pins than the regular Navi 31 package, so it enabled AMD to give the RX 7900 GRE more shaders than the RX 7800 XT, but with the same memory configuration, and a simpler board design than the RX 7900 XT.

To create the Radeon RX 7900 GRE, AMD enabled 80 out of 96 compute units (CU) on the graphics compute die (GCD), resulting in 5,120 stream processors, 160 AI accelerators, 80 Ray accelerators, and 320 TMUs. AMD also enabled 160 out of 192 ROPs available on the silicon. Just four of the six memory cache dies (MCDs) are enabled, each has a 16 MB segment of the GPU's Infinity Cache, and a 64-bit portion of the memory bus. Four of these add up to 64 MB Infinity Cache, and a 256-bit memory bus. AMD is using this to drive 16 GB of 18 Gbps GDDR6 memory, with 576 GB/s of bandwidth on tap—same as that of the RX 6950 XT. The total board power of the RX 7900 GRE is set at 260 W.

The RX 7900 GRE CU count may be close to that of the RX 7900 XT, which has 84, but the XT has other things going for it, such as a wider 320-bit memory bus driving 20 GB of 20 Gbps GDDR6 memory that works out to 38% higher memory bandwidth; besides all 192 ROPs being available. The RX 7800 XT may have a nearly identical memory configuration, but has 25% fewer shaders. So the RX 7900 GRE, on paper, is a nice halfway mark between the RX 7800 XT and RX 7900 XT. If it didn't cost more, this card could have been called something like the "RX 7900 XL," or simply the "RX 7900."

Driving the RX 7900 GRE is AMD's latest RDNA 3 graphics architecture, which is designed to get the most out of the 5 nm foundry node. The Navi 31 is the world's first chiplet-based gaming GPU. AMD identified specific components that benefit the most out of the switch to 5 nm, mainly the shader engines and front-end—and clumped them together on a centralized chiplet called the graphics compute die (GCD). All the components that don't benefit has much, namely the Infinity Cache and GDDR6 memory controllers, are broken apart into tiny chiplets called memory cache dies (MCDs), built on the slightly older 6 nm node. This way, AMD is able to increase its 5 nm wafer utilization. The chiplets are interconnected using Infinity Fanout Links, which make the seven chiplets work like one big chip. This is why the Navi 31 can't be called a multi-chip module: a package that has multiple chips that can otherwise exist on their own packages, but are made to share a package to conserve PCB footprint.

The new RDNA 3 Compute Unit supports dual-issue instruction rate compute units, support for new math formats, and a 17% increase in IPC over RDNA2. The new AI accelerators, two per CU, prepare matrix math workloads for crunching by the stream processors, speeding up this process. The second generation AMD Ray accelerator uses several optimizations to increase ray intersection performance by 50% over the previous generation. There are other improvements, such as a decoupled GPU front-end, which runs at a higher clock speed than the Shader Engines. AMD also significantly updated the display engine to support DisplayPort 2.1 UHBR13, and HDMI 2.1; while the media engines are updated to support AV1 and HEVC encode and decode.

The Sapphire Nitro+ comes with a powerful cooling solution which appears to be carried over from the RX 7800 XT Nitro+. Both the RX 7800 XT and RX 7900 GRE have a nearly identical 260 W total board power, and an identical number of memory chips, so this cooler should perform similarly in both cards. The RX 7800 XT Nitro+ blew us away with massive overclocking potential, thanks in part to the cooler. This beast has a lot of aesthetic and functional features that should appeal to the gamer-streamer or enthusiast crowd, including plenty of RGB LED lighting. Sapphire is pricing the RX 7900 GRE at $600, which is a $50 premium over the AMD baseline and makes its price clash with the RTX 4070 Super.