The Radeon RX 7800 XT is the next piece of the RDNA 3 puzzle. Positioned right below the RX 7900 XT, it is expected to leverage a cut-down Navi 31 die with 16GB of GDDR6 memory and 64MB of L3 cache (Infinity Cache). The Navi 31 GPU on the RX 7800 XT will feature up to 4,480 shaders across 70 CUs (Compute Units). Meanwhile, the memory will be clocked at 20Gbps with a 256-bit bus interface.
The number of active Memory Complex Dies (MCDs) on Navi 31 will be reduced from six to four, each consisting of a 64-bit controller and a 16MB cache chunk. This gives us a 256-bit bus width and 64MB of L3 cache overall. Like the RX 7900 series GPUs, the graphics core should operate a little under 3GHz.
| RX 7900 XTX | RX 7900 XT | RX 7800 XT | RX 6800 XT | |
| Compute units | 96 | 84 | 70 | 72 |
| Shaders | 6,144 | 5,376 | 4,480 | 4,608 |
| Ray Accelerators | 96 | 84 | 70 | 72 |
| Memory | 24GB GDDR6 | 20GB GDDR6 | 16GB GDDR6 | 16GB GDDR6 |
| Memory Speed | 20Gbps | 20Gbps | 20Gbps | 16Gbps |
| Memory Bus Size | 384-bit | 320-bit | 256-bit | 256-bit |
| Game Clock Speed | 2.3GHz | 2GHz | ? | 2GHz |
| L3 Cache | 96MB | 80MB | 64MB | 128MB |
| TBP | 355W | 315W | ? | 300W |
| MSRP | $999 | $899 | ? | $649 |
Benchmarks of the Radeon W7800 indicate that the RX 7800 XT will be 10-15% faster than the RX 6800 XT, 10-20% if you want to be more cautious. The highest gains were observed at 4K, where the 7800 XT averaged 66.4 FPS (vs. 59 FPS on the 6800 XT). At 1440p, the RX 7800 XT posted 119 FPS, while the RX 6800 XT averaged 108 FPS, a delta of just 8%.
Early on, it was believed that the RX 7800 XT would leverage the Navi 32 die, which may yet be true. The fully enabled Navi 32 die features 4,096 shaders across 64 Compute Units (CUs) paired with 64MB of L3 cache and a 256-bit memory controller. Additionally, it packs 256 Texture Units and 128 Raster Output Units alongside 64 RT Cores (one per CU). The GPU has a TBP of 300W and a boost clock of almost 3GHz.
The Radeon RX 7800M XT is the mobile counterpart of the RX 7800 series. It should have the same core specifications as the RX 7800 with a smaller bus and cache. The Radeon RX 7800M XT nets a score of 17,842 in the 3DMark TimeSpy graphics test. This places it on par with NVIDIA’s GeForce RTX 4070 and RTX 3080 desktop graphics cards or a GeForce RTX 4080 mobile. Not bad, considering that the Radeon RX 7900 XT competes with the RTX 4070 Ti desktop GPU.
