AMD Instinct MI308X vs AMD Radeon RX 7800 XT Comparison

The Verdict

The AMD Instinct MI308X and AMD Radeon RX 7800 XT are fundamentally different products aimed at completely separate workloads. The MI308X is an accelerator with no display outputs, no graphics API support, and a thermal design power of 750 W, while the RX 7800 XT is a conventional graphics card with full DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4 support, a 263 W TDP, and a dual-slot form factor with three DisplayPort 2.1 outputs and one HDMI 2.1a output.

The MI308X targets compute-heavy environments where its 192 GB of HBM3 memory and 5.32 TB/s bandwidth matter more than rasterization. The RX 7800 XT targets desktop gaming and workstation use where its 16 GB of GDDR6 memory, 96 ROPs, and 60 ray tracing cores provide the rendering pipeline the MI308X lacks entirely.

The RX 7800 XT holds a 51st percentile ranking among all GPUs in the database, with an average benchmark score of 11627. The MI308X has no recorded benchmarks and sits at the 50th percentile with an average score of 0, meaning the database contains no measured performance data for it. Purchasing decisions must therefore rest on architectural specifications rather than direct comparisons.

Architecture Differences

The MI308X uses the Aqua Vanjaram chip built on CDNA 3.0, a compute-optimized architecture that omits traditional graphics hardware. It packs 153,000 million transistors on a 1017 mm² die, yielding a transistor density of 150.4 million per mm². The RX 7800 XT uses the Navi 32 chip on RDNA 3.0, with 28,100 million transistors on a 346 mm² die, for a density of 81.2 million per mm².

Both chips are fabricated by TSMC on a 5 nm process, but their design philosophies diverge sharply. The MI308X has 19,456 shading units, 1,216 texture mapping units, and zero ROPs. It outputs 0 MPixel/s pixel rate but delivers 2,553.6 GTexel/s texture rate. The RX 7800 XT has 3,840 shading units, 240 TMUs, and 96 ROPs, with a 233.3 GPixel/s pixel rate and 583.2 GTexel/s texture rate.

The MI308X implements no ray tracing cores and no tensor cores in the recorded data. The RX 7800 XT includes 60 ray tracing cores. The MI308X reports no DirectX, OpenGL, or Vulkan support; the RX 7800 XT reports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4.

Memory architecture differs completely. The MI308X uses 192 GB of HBM3 across an 8192-bit bus, achieving 5.32 TB/s bandwidth. The RX 7800 XT uses 16 GB of GDDR6 across a 256-bit bus, achieving 624.1 GB/s. Clock behavior also differs: the MI308X runs at a 1000 MHz base and 2100 MHz boost, while the RX 7800 XT runs at 1295 MHz base, 2124 MHz game clock, and 2430 MHz boost.

FAQ

Q: Does the AMD Instinct MI308X support graphics rendering?

A: No. The MI308X has no display outputs, no ROPs, and reports N/A for DirectX, OpenGL, and Vulkan APIs. Its pixel rate is 0 MPixel/s, confirming it cannot rasterize images.

Q: What memory capacity does each card offer?

A: The MI308X offers 192 GB of HBM3 memory with a 5.32 TB/s bandwidth. The RX 7800 XT offers 16 GB of GDDR6 memory with a 624.1 GB/s bandwidth.

Q: Which card has a higher boost clock?

A: The RX 7800 XT has a higher boost clock at 2430 MHz, compared to the MI308X boost clock of 2100 MHz.

Q: What are the power requirements for each card?

A: The MI308X has a 750 W TDP and requires a suggested 1150 W power supply. The RX 7800 XT has a 263 W TDP and requires a suggested 600 W power supply.

Q: Does the MI308X have any benchmark results in the database?

A: No. The MI308X has an empty benchmarks array, an average benchmark score of 0, and no nearest rivals. The RX 7800 XT has ten recorded benchmark scores across 3DMark, Geekbench, and Passmark tests.

Q: What is the form factor difference?

A: The MI308X is an OAM Module with no power connectors and no display outputs. The RX 7800 XT is a dual-slot card measuring 267 mm in length, 111 mm in height, and 50 mm in width, with two 8-pin power connectors.

Specification Differences

| Specification | AMD Instinct MI308X | AMD Radeon RX 7800 XT |

|---|---|---|

| Chip | Aqua Vanjaram | Navi 32 |

| Architecture | CDNA 3.0 | RDNA 3.0 |

| Transistors | 153,000 million | 28,100 million |

| Die Size | 1017 mm² | 346 mm² |

| Transistor Density | 150.4M / mm² | 81.2M / mm² |

| Base Clock | 1000 MHz | 1295 MHz |

| Boost Clock | 2100 MHz | 2430 MHz |

| Game Clock | None | 2124 MHz |

| Memory Size | 192 GB | 16 GB |

| Memory Type | HBM3 | GDDR6 |

| Memory Bus | 8192 bit | 256 bit |

| Memory Bandwidth | 5.32 TB/s | 624.1 GB/s |

| Shading Units | 19456 | 3840 |

| TMUs | 1216 | 240 |

| ROPs | 0 | 96 |

| Ray Tracing Cores | None | 60 |

| Pixel Rate | 0 MPixel/s | 233.3 GPixel/s |

| Texture Rate | 2,553.6 GTexel/s | 583.2 GTexel/s |

| FP32 | 81.72 TFLOPS | 37.32 TFLOPS |

| FP16 | 81.72 TFLOPS (1:1) | 37.32 TFLOPS (1:1) |

| TDP | 750 W | 263 W |

| Slot Width | OAM Module | Dual-slot |

| Power Connectors | None | 2x 8-pin |

| Suggested PSU | 1150 W | 600 W |

| Bus Interface | PCIe 5.0 x16 | PCIe 4.0 x16 |

| Display Outputs | No outputs | 1x HDMI 2.1a, 3x DisplayPort 2.1 |

| DirectX | N/A | 12 Ultimate (12_2) |

| OpenGL | N/A | 4.6 |

| Vulkan | N/A | 1.4 |

| Dimensions | Not recorded | 267 mm x 111 mm x 50 mm |

| Production Status | Not recorded | Active |

| Release Date | 2023-12-05 | 2023-09-05 |

| Predecessor | Radeon Instinct | Navi II |

| Successor | None | Navi IV |

Head-to-Head Benchmarks

The database contains no head-to-head benchmark entries between these two cards, and the MI308X has no recorded benchmark scores of any kind. The RX 7800 XT, however, has ten recorded results that establish its performance profile.

In 3DMark Steel Nomad DX12, the RX 7800 XT scores 4157. Geekbench OpenCL returns 18290, and Geekbench Vulkan returns 54228. Passmark results show 24176 in G3D, 13473 in GPU Compute, 1177 in G2D, 304 in DirectX 9, 249 in DirectX 11, 121 in DirectX 10, and 93 in DirectX 12.

The RX 7800 XT averages 11627 across all benchmarks, placing it at the 51st percentile. Its nearest rivals in the database are the NVIDIA GeForce GTX 1660 at 11680 (0.5% higher), the AMD Radeon Pro 5500M at 11528 (0.9% lower), the NVIDIA Tesla K20c at 11479 (1.3% lower), and the AMD Radeon RX 6500 XT at 11842 (1.8% higher). The RX 7800 XT trails the GTX 1660 by 0.5% and the RX 6500 XT by 1.8%, while leading the Radeon Pro 5500M by 0.9% and the Tesla K20c by 1.3%.

The MI308X cannot be compared through these metrics. Its FP32 throughput of 81.72 TFLOPS is more than double the RX 7800 XT's 37.32 TFLOPS, and its texture rate of 2,553.6 GTexel/s is 4.4 times higher than the RX 7800 XT's 583.2 GTexel/s. Those figures indicate raw compute capacity, but the MI308X lacks the rendering pipeline to turn that into graphics output.

Where Each One Wins

The MI308X wins in raw compute throughput. Its 81.72 TFLOPS FP32 and FP16 performance, 192 GB memory capacity, and 5.32 TB/s bandwidth position it for large-scale data processing, scientific simulation, and AI workloads where memory capacity and bandwidth dominate. The 8192-bit memory bus provides 8.5 times the bandwidth of the RX 7800 XT. The higher transistor count of 153,000 million versus 28,100 million reflects a much larger compute array, and the PCIe 5.0 x16 interface doubles the bus bandwidth available to the RX 7800 XT's PCIe 4.0 x16.

The RX 7800 XT wins in every graphics-oriented category. It delivers a 233.3 GPixel/s pixel rate where the MI308X delivers 0. It has 96 ROPs where the MI308X has none. It supports DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4; the MI308X supports none of these. It has 60 ray tracing cores, display outputs, and a dual-slot form factor that fits in a standard desktop case. The RX 7800 XT also draws 263 W versus 750 W and requires a 600 W power supply versus 1150 W.

The RX 7800 XT also has a measurable performance record. Its average benchmark score of 11627 and 51st percentile ranking come from ten tests spanning DirectX 9 through DirectX 12, OpenCL, Vulkan, G2D, G3D, and GPU compute. The MI308X has no benchmark results, no nearest rivals, and no percentile context beyond a default 50th percentile.

For gaming, rendering, or any task requiring a display output, the RX 7800 XT is the only viable option. For server-side compute without graphics, the MI308X offers memory and throughput characteristics that the RX 7800 XT cannot approach. The release dates differ by three months, with the RX 7800 XT launching on 2023-09-05 and the MI308X on 2023-12-05. The RX 7800 XT remains in active production; the MI308X production status is not recorded.