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After our launch-day review of AMD's RX 7900 XTX went live earlier this month, it's time to take a look at our first partner card. Sapphire's Nitro+ series has a long history of quality designs, and we would hope for no different from this new RDNA 3-based card. Offering a very sleek design, dual-BIOS, and a power limit increased all the way up to 420W, there's a lot going for this card on paper, so let's see how much of an improvement it really is versus AMD's reference design.
The Sapphire Nitro+ series has undergone quite a change since we last looked at the previous generation of cards. Plenty of core features remain, including Quick Connect, Dual-BIOS (including a software switch mode), and the Tri-X fan system, but alongside the aesthetic changes, Sapphire has also brought back its Vapor-X technology, meaning the GPU and memory modules are cooled via a vapour chamber.
It's certainly a looker, and we've come to expect very good things from the Nitro+ brand over the years, so let's find out if this RX 7900 XTX can live up to its billing.
| RX 7900 XTX | RX 7900 XT | RX 6950 XT | RX 6900 XT | RX 6800 XT | RX 6800 | |
| Architecture | RDNA 3 | RDNA 3 | RDNA 2 | RDNA 2 | RDNA 2 | RDNA 2 |
| Manufacturing Process | 5nm GCD + 6nm MCD | 5nm GCD + 6nm MCD | 7nm | 7nm | 7nm | 7nm |
| Transistor Count | 57.7 billion | 57.7 billion | 26.8 billion | 26.8 billion | 26.8 billion | 26.8 billion |
| Die Size | 300 mm² GCD 220 mm² MCD | 300 mm² GCD 220 mm² MCD | 519 mm² | 519 mm² | 519 mm² | 519 mm² |
| Ray Accelerators | 96 | 84 | 80 | 80 | 72 | 60 |
| Compute Units | 96 | 84 | 80 | 80 | 72 | 60 |
| Stream Processors | 6144 | 5376 | 5120 | 5120 | 4608 | 3840 |
| Game GPU Clock | Up to 2300MHz | Up to 2000 MHz | Up to 2100MHz | Up to 2015MHz | Up to 2015MHz | Up to 1815MHz |
| Boost GPU Clock | Up to 2500 MHz | Up to 2400 MHz | Up to 2310MHz | Up to 2250MHz | Up to 2250MHz | Up to 2105MHz |
| ROPs | 192 | 192 | 128 | 128 | 128 | 96 |
| AMD Infinity Cache | 96MB | 80MB | 128MB | 128MB | 128MB | 128MB |
| Memory | 24GB GDDR6 | 20GB GDDR6 | 16GB GDDR6 18Gbps | 16GB GDDR6 16Gbps | 16GB GDDR6 | 16GB GDDR6 |
| Memory Bandwidth | 960 GB/s | 800 GB/s | 576 GB/s | 512 GB/s | 512 GB/s | 512 GB/s |
| Memory Interface | 384-bit | 320-bit | 256-bit | 256-bit | 256-bit | 256-bit |
| Board Power | 355W | 315W | 335W | 300W | 300W | 250W |
First, let's take a quick look at the specs. The RDNA 3 architecture has seen AMD transition to a chiplet-based design – a world first for a gaming GPU. We find a 300mm² Graphics Compute Die, based on TSMC's 5nm node, flanked by six 37mm² Memory Cache Dies. In total, the Navi 31 GPU packs 57.7 billion transistors.
Internally, the GCD makeup hasn't been radically changed compared to what we saw with RDNA 2. That means Navi 31 packs in 96 Compute Units, each of which houses 64 Steam Processors, for a total of 6144 shaders. There's also 96 Ray Accelerators – one per CU – and 192 ROPs.
As for clock speed, AMD has de-coupled the clocks, so the front-end and shaders can operate at different clock speeds in a bid to save power. With the RX 7900 XTX, the shader clock features a rated game clock of up to 2300MHz, and a boost of up to 2500MHz. Sapphire has increased this figure however, with the primary BIOS operating with a 2680MHz boost clock.
Meanwhile, the memory configuration has taken a step forward. The RX 7900 XTX packs 24GB of GDDR6 memory clocked at 20Gbps, operating over a 384-bit memory interface, for total memory bandwidth of 960 GB/s. 96MB of Infinity Cache is also present, which allows AMD to claim an ‘effective memory bandwidth' of up to 3500 GB/s.
Power draw for the RX 7900 XTX is rated at 355W Total Board Power (TBP), but Sapphire has increased this further, up to a 420W TBP for the Nitro+ using the primary BIOS, though the secondary BIOS is more conservative at 350W.
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