PowerColor RX 7900 GRE Hellhound Review

1. Introduction2. Meet the PowerColor RX 7900 GRE Hellhound3. Testing Methodology4. Game Benchmarks5. Clock Speed6. GPU Temperatures7. Acoustics8. Noise-Normalised Temperatures9. Power Draw and Efficiency10. Overclocking11. Closing Thoughts12. View All Pages

Today we are taking a look at a highly-requested graphics card – the PowerColor RX 7900 GRE Hellhound. It's been some time since we last looked at one of these GPUs, and with the Hellhound available at £549, it will be interesting to see how it stacks up not only against other 7900 GRE models, but also against Nvidia's RTX 4070 Super. We assess thermals, noise levels, gaming performance, power draw and more to find out if this card is worth buying.

	RX 7900 XTX	RX 7900 XT	RX 7900 GRE	RX 7800 XT	RX 7700 XT
Architecture	RDNA 3	RDNA 3	RDNA 3	RDNA 3	RDNA 3
Manufacturing Process	5nm GCD + 6nm MCD	5nm GCD + 6nm MCD	5nm GCD + 6nm MCD	5nm GCD + 6nm MCD	5nm GCD + 6nm MCD
Transistor Count	57.7 billion	57.7 billion	57.7 billion	28.1 billion	28.1 billion
Die Size	300 mm² GCD 220 mm² MCD	300 mm² GCD 220 mm² MCD	300 mm² GCD 220 mm² MCD	200 mm² GCD 150 mm² MCD	200 mm² GCD 150 mm² MCD
Compute Units	96	84	80	60	54
Ray Accelerators	96	84	80	60	54
Stream Processors	6144	5376	5120	3840	3456
Game GPU Clock	Up to 2300MHz	Up to 2000 MHz	1880 MHz	2124 MHz	2171 MHz
Boost GPU Clock	Up to 2500 MHz	Up to 2400 MHz	Up to 2245 MHz	Up to 2430 MHz	Up to 2544 MHz
ROPs	192	192	192	96	96
AMD Infinity Cache	96MB	80MB	64MB	64MB	48MB
Memory	24GB GDDR6	20GB GDDR6	16GB GDDR6	16GB GDDR6	12GB GDDR6
Memory Data Rate	20 Gbps	20 Gbps	18 Gbps	19.5 Gbps	18 Gbps
Memory Bandwidth	960 GB/s	800 GB/s	576 GB/s	624 GB/s	432 GB/s
Memory Interface	384-bit	320-bit	256-bit	256-bit	192-bit
Board Power	355W	315W	260 W	263W	245W

First, let's take a quick look at the specs. The RX 7900 GRE is using the same Navi 31 die that we first saw with the RX 7900 XTX and 7900 XT, but it has been significantly cut-down. Still, using the same die means we find a 300mm² Graphics Compute Die, based on TSMC's 5nm node, flanked by six 37mm² Memory Cache Dies (though two are disabled for the 7900 GRE). In total, the Navi 31 GPU packs 57.7 billion transistors.

While a full Navi 31 GPU packs in 96 Compute Units, the 7900 GRE is cut down to 80 CUs, 4 fewer than the 7900 XT, and each CU houses 64 Steam Processors, for a total of 5120 shaders. There's also 80 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 GRE, the Hellhound does come factory overclocked, with a boost at 2366MHz when using the OC BIOS.

The memory configuration is where we see the biggest change compared to the 7900 XT, however. With two of the six MCDs disabled, the RX 7900 GRE packs 16GB of GDDR6 memory clocked at 18Gbps, operating over a 256-bit memory interface, for total memory bandwidth of 576 GB/s. 64MB of Infinity Cache is also present, which allows AMD to claim an ‘effective memory bandwidth' of up to 2265.6 GB/s.

Power draw for the RX 7900 GRE is also rated at 260W Total Board Power (TBP), but the Hellhound has increased this up to 280W.

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