KitGuru KitGuru.net – Tech News | Hardware News | Hardware Reviews | IOS | Mobile | Gaming | Graphics Cards
Following on from our launch day review of AMD's reference RX 7800 XT graphics card, today we turn our attention to the partner cards, and the PowerColor Hellhound in particular. Offering a beefed-up triple fan cooler, dual-BIOS and a physical switch to control the lighting, this card hits the market at around £520. Is it worth paying the £40 premium for? We find out today.
We were generally impressed with the RX 7800 XT in our launch day review, and while it's not a huge step forward from the previous generation, it does offer convincing value against the likes of the RTX 4060 Ti and RTX 4070. While AMD's own RX 7800 XT reference (MBA) card was decent, we'd expect an experienced partner like PowerColor to improve on pretty much everything with the RX 7800 XT Hellhound, so let's find out what this card can bring to the table.
| RX 7900 XT | RX 7800 XT | RX 7700 XT | RX 6800 XT | RX 6800 | RX 6700 XT | |
| Architecture | RDNA 3 | RDNA 3 | RDNA 3 | RDNA 2 | RDNA 2 | RDNA 2 |
| Manufacturing Process | 5nm GCD + 6nm MCD | 5nm GCD + 6nm MCD | 5nm GCD + 6nm MCD | 7nm | 7nm | 7nm |
| Transistor Count | 57.7 billion | 28.1 billion | 28.1 billion | 26.8 billion | 26.8 billion | 17.2 billion |
| Die Size | 300 mm² GCD
220 mm² MCD |
200 mm² GCD
150 mm² MCD |
200 mm² GCD
150 mm² MCD |
519 mm² | 519 mm² | 336 mm² |
| Compute Units | 84 | 60 | 54 | 72 | 60 | 40 |
| Ray Accelerators | 84 | 60 | 54 | 72 | 60 | 40 |
| Stream Processors | 5376 | 3840 | 3456 | 4608 | 3840 | 2560 |
| Game GPU Clock | Up to 2000 MHz | 2124 MHz | 2171 MHz | Up to 2015MHz | Up to 1815MHz | Up to 2424MHz |
| Boost GPU Clock | Up to 2400 MHz | Up to 2430 MHz | Up to 2544 MHz | Up to 2250MHz | Up to 2105MHz | Up to 2581MHz |
| ROPs | 192 | 96 | 96 | 128 | 96 | 64 |
| AMD Infinity Cache | 80MB | 64MB | 48MB | 128MB | 128MB | 96MB |
| Memory | 20GB GDDR6 20Gbps | 16GB GDDR6 19.5 Gbps | 12GB GDDR6 18Gbps | 16GB GDDR6 16Gbps | 16GB GDDR6 16Gbps | 12GB GDDR6 16Gbps |
| Memory Bandwidth | 800 GB/s | 624 GB/s | 432 GB/s | 512 GB/s | 512 GB/s | 384 GB/s |
| Memory Interface | 320-bit | 256-bit | 192-bit | 256-bit | 256-bit | 192-bit |
| Board Power | 315W | 263W | 245W | 300W | 250W | 230W |
OC BIOS, left, compared to Silent BIOS, right
First, let's take a quick look at the specs. Unlike the most recent RDNA 3 GPU – the RX 7600 – AMD has made a return to its chiplet-based design for the RX 7800 XT, as we initially saw last year with the RX 7900 XTX and 7900 XT. This time around, the 7800 XT offers a 200mm² Graphics Compute Die (GCD) using TSMC's 5nm process, flanked by four 150 mm² Memory Compute Dies (MCDs) built on TSMC's 6nm node.
Internally though, the compute makeup hasn't been radically changed. Navi 32 packs in 60 Compute Units, each of which houses 64 Stream Processors, for a total of 3840 shaders. There are also 60 Ray Accelerators – one per CU – and 96 ROPs.
As for clock speed, this remains high with the RX 7800 XT, with AMD touting a reference boost clock of up to 2430MHz. PowerColor has tweaked this up to 2520MHz for the OC BIOS however, while the Silent BIOS remains at stock clocks.
Meanwhile, the memory configuration is almost identical to the previous generation RX 6800 XT. We still find 16GB GDDR6 operating over a 256-bit interface, but this time the memory clocks in at 19.5Gbps, up from 16Gbps. This gives a memory bandwidth of 624 GB/s, though AMD claims an ‘effective' bandwidth of 2708.4 GB/s due to the 64MB of 2nd Gen Infinity cache.
Power draw for the RX 7800 XT is rated at 263W Total Board Power (TBP), though PowerColor has again increased this for the OC BIOS. We are using our well-established GPU power testing methodology in this review, so read on for our most detailed power and efficiency testing yet.
