AMD Radeon Instinct MI25 vs AMD Radeon RX 6850M XT Comparison

The AMD Radeon RX 685M XT and the AMD Radeon Instinct MI25 represent two very different eras and design philosophies from the same manufacturer. The data shows a clear performance hierarchy, but the comparison is nuanced by architectural and feature-set differences. The RX 6850M XT holds a decisive performance lead in the only shared benchmark, but the MI25 offers distinct capabilities in memory capacity and form factor that may serve specific professional workloads.

Head-to-Head Benchmarks

The benchmark database provides one direct comparison point between these two GPUs: the Geekbench OpenCL test. The results are unambiguous. The AMD Radeon RX 6850M XT scores 85,040 points, while the AMD Radeon Instinct MI25 scores 68,562 points. This translates to a 24% advantage for the RX 6850M XT, making it the winner in this head-to-head matchup.

This 24% delta is substantial. To put it in perspective, the RX 6850M XT's average benchmark score across all tests is 78,940, placing it in the 92nd percentile of all GPUs. Its nearest rivals include the NVIDIA GeForce RTX 5090, which scores 79,842 (1.1% higher), and the NVIDIA Tesla P100 PCIe 16 GB, which scores 79,605 (0.8% higher). The RX 6850M XT is essentially trading blows with these high-end cards, sitting just 0.6% behind the Tesla P100 PCIe 12 GB's score of 79,396.

The MI25, by contrast, has an average benchmark score of 68,562, placing it in the 90th percentile. Its closest competitor is the Intel Arc A770, which scores 68,809 (0.4% higher). The MI25 sits 1.9% behind the AMD Radeon Pro WX 8200 and 2% behind the NVIDIA Quadro P6000. While the percentile ranking is close, the absolute performance gap between the two cards is significant.

The data shows that the RX 6850M XT is not just faster in this single test; it is categorically in a higher performance tier. The 24% lead in OpenCL compute is a strong indicator of its overall capability. The MI25, while still a competent performer in its own right, is clearly a generation behind in raw compute throughput.

Architecture Differences

The architectural divide between these two GPUs is fundamental. The RX 6850M XT is built on the RDNA 2.0 architecture using the Navi 22 chip, manufactured on a 7 nm process at TSMC. The MI25 uses the older GCN 5.0 architecture with the Vega 10 chip, built on a 14 nm process at GlobalFoundries. This process node difference alone—7 nm versus 14 nm—explains a significant portion of the performance and efficiency gap.

The transistor counts reflect the architectural generation gap. The RX 6850M XT packs 17,200 million transistors onto a 335 mm² die, achieving a transistor density of 51.3M / mm². The MI25 has 12,500 million transistors on a much larger 495 mm² die, resulting in a density of only 25.3M / mm². The RX 6850M XT is more than twice as dense, a direct result of the more advanced process node.

Core configurations differ markedly. The RX 6850M XT features 2,560 shading units, 160 texture mapping units (TMUs), and 64 raster operation pipelines (ROPs). It also includes 40 dedicated ray tracing cores, a feature entirely absent from the MI25. The MI25 counters with 4,096 shading units and 256 TMUs, but also has 64 ROPs. Despite having 60% more shading units, the MI25's older architecture and lower clocks prevent it from translating that raw count into superior performance.

Clock speeds are where the RX 6850M XT truly separates itself. It runs at a base clock of 2321 MHz and a boost clock of 2581 MHz, with a game clock of 2463 MHz. The MI25 is much slower, with a base clock of 1400 MHz and a boost of 1500 MHz. This nearly 1 GHz difference in boost clock is a primary driver of the RX 6850M XT's performance advantage.

Memory subsystems also diverge. The RX 6850M XT uses 12 GB of GDDR6 memory on a 192-bit bus, delivering 432.0 GB/s of bandwidth. The MI25 uses 16 GB of HBM2 memory on a massive 2048-bit bus, achieving 436.2 GB/s. The bandwidth figures are nearly identical, but the MI25's larger capacity and wider bus are geared toward different workloads.

Where Each One Wins

The RX 6850M XT wins decisively in raw computational performance. Its 13.21 TFLOPS of FP32 compute and 26.43 TFLOPS of FP16 (2:1) are higher than the MI25's 12.29 TFLOPS and 24.58 TFLOPS, respectively. The pixel rate also favors the RX 6850M XT at 165.2 GPixel/s versus the MI25's 96.00 GPixel/s, and the texture rate is 413.0 GTexel/s versus 384.0 GTexel/s. In every measurable performance metric, the RX 6850M XT leads.

The MI25's advantages are more situational. Its 16 GB of HBM2 memory, compared to the RX 6850M XT's 12 GB, provides a larger memory pool for applications that require massive datasets. Its dual-slot, 267 mm length form factor with 2x 8-pin power connectors and a 700 W suggested PSU indicates it is designed for a workstation or server environment, not a portable device.

The RX 6850M XT is an integrated graphics processor (IGP) with no power connectors, designed for mobile devices. Its display outputs are "Portable Device Dependent," meaning it relies on the host laptop for connectivity. The MI25, conversely, has no display outputs at all—it is a pure compute accelerator.

FAQ

Q: Which GPU is faster in the Geekbench OpenCL benchmark?

A: The AMD Radeon RX 6850M XT scores 85,040 points, which is 24% higher than the AMD Radeon Instinct MI25's score of 68,562 points.

Q: Does the MI25 have any performance advantage over the RX 6850M XT?

A: No. The RX 6850M XT leads in all direct performance metrics, including FP32 compute (13.21 vs 12.29 TFLOPS) and pixel rate (165.2 vs 96.00 GPixel/s).

Q: What is the biggest architectural difference between the two?

A: The RX 6850M XT uses the RDNA 2.0 architecture on a 7 nm process, while the MI25 uses GCN 5.0 on a 14 nm process. The RX 6850M XT also includes 40 ray tracing cores, which the MI25 lacks.

Q: How do their memory capacities compare?

A: The MI25 has 16 GB of HBM2 memory on a 2048-bit bus, while the RX 6850M XT has 12 GB of GDDR6 on a 192-bit bus. Their bandwidth is nearly identical at 436.2 GB/s versus 432.0 GB/s.

Q: Are these GPUs still in production?

A: No. Both the AMD Radeon RX 6850M XT and the AMD Radeon Instinct MI25 are listed as end-of-life products.

Q: Which GPU has a higher benchmark percentile ranking?

A: The RX 6850M XT ranks in the 92nd percentile of all GPUs, compared to the MI25's 90th percentile.

The Verdict

The data presents a clear choice. The AMD Radeon RX 6850M XT is the superior performer in every benchmark metric that was measured. Its 24% lead in OpenCL, combined with higher FP32 and FP16 compute, higher pixel and texture rates, and a more advanced architecture, make it the obvious choice for any workload where raw compute power is the priority. Its 92nd percentile ranking, placing it in the company of the NVIDIA GeForce RTX 5090, underscores its high-end positioning.

The AMD Radeon Instinct MI25, however, serves a different purpose. Its 16 GB of HBM2 memory and dual-slot, 267 mm form factor indicate a design intent for server racks and data center compute tasks where memory capacity and reliability are more critical than raw speed. Its 90th percentile ranking shows it is still competitive, but it is a legacy product from an older era.

For a user seeking maximum performance in a mobile or general-purpose scenario, the RX 6850M XT is the only rational choice. For a professional with a specific need for a large memory pool in a data center accelerator, the MI25's larger memory capacity is its sole practical advantage. The performance gap, however, is too significant to ignore, and the RX 6850M XT emerges as the more capable overall GPU.

Specification Differences

| Specification | AMD Radeon RX 6850M XT | AMD Radeon Instinct MI25 |

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

| Architecture | RDNA 2.0 | GCN 5.0 |

| Process Node | 7 nm | 14 nm |

| Transistors | 17,200 million | 12,500 million |

| Die Size | 335 mm² | 495 mm² |

| Base Clock | 2321 MHz | 1400 MHz |

| Boost Clock | 2581 MHz | 1500 MHz |

| Memory Size | 12 GB | 16 GB |

| Memory Type | GDDR6 | HBM2 |

| Memory Bus | 192 bit | 2048 bit |

| Memory Clock | 2250 MHz (18 Gbps effective) | 852 MHz (1704 Mbps effective) |

| Shading Units | 2560 | 4096 |

| TMUs | 160 | 256 |

| ROPs | 64 | 64 |

| Ray Tracing Cores | 40 | None |

| FP32 Performance | 13.21 TFLOPS | 12.29 TFLOPS |

| FP16 Performance | 26.43 TFLOPS (2:1) | 24.58 TFLOPS (2:1) |

| Pixel Rate | 165.2 GPixel/s | 96.00 GPixel/s |

| Texture Rate | 413.0 GTexel/s | 384.0 GTexel/s |

| TDP | 165 W | 300 W |

| Slot Width | IGP | Dual-slot |

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

| Suggested PSU | None | 700 W |

| Bus Interface | PCIe 4.0 x16 | PCIe 3.0 x16 |

| Display Outputs | Portable Device Dependent | No outputs |

| DirectX Support | 12 Ultimate (12_2) | 12 (12_1) |

| Vulkan Support | 1.4 | 1.3 |

| Release Date | 2022-01-03 | 2017-06-26 |