AMD Instinct MI100 vs AMD Radeon Instinct MI25 Comparison

Head-to-Head Benchmarks

The only recorded benchmark in the database for both accelerators is Geekbench OpenCL. The AMD Instinct MI100 posts a score of 139,035, while the AMD Radeon Instinct MI25 posts 68,562. The MI100 wins this test outright, with a delta of 102.8% over the MI25. In practical terms, the MI100 is more than twice as fast in this compute workload.

The MI100’s score places it at the 96th percentile among all GPUs in the database. Its nearest rivals are all NVIDIA Tesla V100 variants: the V100 PCIe 16 GB scores 138,063 (0.7% behind), the V100 SXM2 32 GB scores 137,731 (0.9% behind), the AMD Radeon PRO V620 scores 136,472 (1.9% behind), and the AMD Radeon Pro W6800X Duo scores 135,774 (2.4% behind). The MI100 leads this cluster by a narrow margin, indicating that its raw OpenCL performance sits just above a group of strong data center and workstation parts.

The MI25’s 68,562 score places it at the 90th percentile. Its nearest rivals are clustered tightly around it: the Intel Arc A770 scores 68,809 (0.4% higher, so the MI25 is 0.4% behind), the NVIDIA CMP 90HX scores 69,000 (0.6% higher, so the MI25 is 0.6% behind), the AMD Radeon Pro WX 8200 scores 69,870 (1.9% behind the MI25), and the NVIDIA Quadro P6000 scores 69,986 (2.0% behind the MI25). The MI25 is essentially in a dead heat with these parts, just a hair below the Arc A770 and CMP 90HX but slightly above the WX 8200 and P6000.

The delta between the two AMD accelerators is enormous: 102.8%. That is not a marginal generation-over-generation gain; it is a complete tier shift. The MI100’s score is nearly double the MI25’s score. In the database, a 102.8% delta between two products is a decisive separation, not a competitive race. The MI100 is clearly in a different performance class.

Architecture Differences

The MI100 is built on the CDNA 1.0 architecture, while the MI25 uses GCN 5.0. These are fundamentally different design families for compute-focused workloads.

The manufacturing process differs sharply. The MI100 is fabricated on a 7 nm process at TSMC, while the MI25 is built on a 14 nm process at GlobalFoundries. This process gap explains much of the efficiency and density difference. The MI100 packs 25,600 million transistors onto a 750 mm² die, resulting in a transistor density of 34.1 million per mm². The MI25 has 12,500 million transistors on a 495 mm² die, for a density of 25.3M per mm². The MI100 has roughly twice the transistor count on a die that is only about 50% larger.

The MI25’s architecture is older and less compute-specialized. It is built around the Vega 10 chip. The MI100’s Arcturus chip is a larger, more complex design. The MI100 has no display outputs, and the MI25 also has none, but the MI25 does support a full set of graphics APIs: DirectX 12 (12_1), OpenGL 4.6, and Vulkan 1.3. The MI100 lists N/A for DirectX, OpenGL, and Vulkan, which indicates it is not a graphics card at all, it is a pure compute accelerator.

The bus interface also differs. The MI100 uses PCIe 4.0 x16, while the MI25 uses PCIe 3.0 x16. This doubles the theoretical interconnect bandwidth for the newer part, which can matter for data transfer in multi-GPU or host-memory-heavy workloads.

The memory subsystem is a major architectural divergence. The MI100 has 32 GB of HBM2 on a 4096-bit bus, yielding 1.23 TB/s of bandwidth. The MI25 has 16 GB of HBM2 on a 2048-bit bus, yielding 436.2 GB/s. The MI100 has double the capacity, double the bus width, and nearly three times the bandwidth. The MI25’s memory clock is 852 MHz (1704 Mbps effective), while the MI100’s memory clock is 1200 MHz (2.4 Gbps effective). The MI100’s memory clock is also higher.

The compute unit counts follow the same pattern. The MI100 has 7,680 shading units, 480 TMUs, and 64 ROPs. The MI25 has 4,096 shading units, 256 TMUs, and 64 ROPs. The MI100 has nearly double the shading units and TMUs, while the ROP count is identical at 64.

Neither part has dedicated ray tracing cores or tensor cores. Both are pure compute/rendering designs without those specialized units.

The clock speeds are interesting. The MI25 runs a base clock of 1400 MHz and a boost clock of 1500 MHz. The MI100 runs a base of 1000 MHz and a boost of 1502 MHz. The MI25 has a higher base clock, but the boost clocks are nearly identical. The MI100’s performance advantage does not come from raw frequency; it comes from the greater width of the execution units and the memory subsystem.

The pixel rate is essentially identical: 96.13 GPixel/s for the MI100 and 96.00 GPixel/s for the MI25. The texture rate is very different: 721.0 GTexel/s for the MI100 vs 384.0 GTexel/s for the MI25. The MI100 has nearly double the texture throughput.

The FP32 and FP16 throughput numbers tell the same story. The MI100 delivers 23.07 TFLOPS FP32 and 46.14 TFLOPS FP16 (2:1). The MI25 delivers 12.29 TFLOPS FP32 and 24.58 TFLOPS FP16 (2:1). The MI100 is roughly 1.9x faster in both precisions.

The power configuration is identical on paper: both are 300 W TDP, dual-slot, with 2x 8-pin power connectors and a 700 W suggested PSU. The MI25 achieves its 300 W at 14 nm with a much smaller chip; the MI100 does it at 7 nm with a much larger chip. The MI100 is more power-efficient per unit of compute, as evidenced by the higher performance at the same TDP.

The MI100 is the newer part, released in late 2020, while the MI25 was released in mid-2017. Both are end-of-life. The MI100’s predecessor is listed as Radeon Instinct, and the MI25’s predecessor is FirePro Data Center. Neither has a successor listed.

The Verdict

The data is unambiguous: the AMD Instinct MI100 is the overwhelmingly faster accelerator. In the Geekbench OpenCL test, it beats the MI25 by 102.8%, meaning it delivers more than double the raw compute score. Its nearest rivals are the NVIDIA Tesla V100 variants, and it edges them out by 0.7% to 2.4%. The MI25, by contrast, sits in a cluster with consumer and workstation parts like the Intel Arc A770 and NVIDIA Quadro P6000, where it is roughly equal.

The MI100 is the correct choice for anyone who needs the highest compute throughput per card. It has 32 GB of HBM2 with 1.2 TB/s of bandwidth, which is double the capacity and nearly triple the bandwidth of the MI25. It has 7,680 shading units vs 4,096. It has more than double the FP32 and FP16 throughput. It is built on a modern 7 nm process with PCIe 4.0. The only thing the MI25 has going for it in the data is a higher base clock (1400 vs 1000 MHz) and a full set of graphics APIs.

The MI25 is the correct choice for someone who needs a compute accelerator with graphics API support. The MI25 supports DirectX 12, OpenGL 4.6, and Vulkan 1.3, while the MI100 supports none of these. If the workload requires those APIs, the MI25 is the only one of the two that can do it. The MI100 has no display outputs and no graphics API support, which is clear evidence that it is purely a compute device.

For compute-heavy workloads without a graphics API requirement, the MI100 is the obvious choice. The 102.8% performance delta is too large to ignore. The MI25 is not competitive in raw compute terms; it is in a different performance tier.

For workloads that need the graphics APIs or that are memory-constrained, the answer is more nuanced. The MI25 has 16 GB of memory, which is less than the MI100’s 32 GB, but it does have the graphics API support. The MI100’s lack of DirectX, OpenGL, and Vulkan support means it cannot be used as a general-purpose GPU for those workloads.

The MI25 also has a higher base clock, which may be relevant for workloads that are latency-bound. But the MI100’s boost clock is essentially the same (1500 vs 1502 MHz), so the MI25’s advantage is only in the sustained base clock.

The data clearly indicates that for compute workloads, the MI100 is the better buy. It is in a different performance class. The MI25 is a valid option for older systems that need graphics API support, but it is not a compute competitor to the MI100.

Specification Differences

| Field | AMD Instinct MI100 | AMD Radeon Instinct MI25 |

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

| Architecture | CDNA 1.0 | GCN 5.0 |

| Process Node | 7 nm | 14 nm |

| Foundry | TSMC | GlobalFoundries |

| Transistors | 25,600 million | 12,500 million |

| Die Size | 750 mm² | 495 mm² |

| Transistor Density | 34.1M / mm² | 25.3M / mm² |

| Base Clock | 1000 MHz | 1400 MHz |

| Boost Clock | 1502 MHz | 1500 MHz |

| Memory Clock | 1200 MHz, 2.4 Gbps effective | 852 MHz, 1704 Mbps effective |

| Memory Size | 32 GB | 16 GB |

| Memory Bus Width | 4096 bit | 2048 bit |

| Memory Bandwidth | 1.23 TB/s | 436.2 GB/s |

| Shading Units | 7680 | 4096 |

| TMUs | 480 | 256 |

| Pixel Rate | 96.13 GPixel/s | 96.00 GPixel/s |

| Texture Rate | 721.0 GTexel/s | 384.0 GTexel/s |

| FP32 | 23.07 TFLOPS | 12.29 TFLOPS |

| FP16 | 46.14 TFLOPS | 24.58 TFLOPS |

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

| DirectX | N/A | 12 (12_1) |

| OpenGL | N/A | 4.6 |

| Vulkan | N/A | 1.3 |

| Release Date | 2020-11-15 | 2017-06-26 |

| Predecessor | Radeon Instinct | FirePro Data Center |

The two accelerators share identical TDP (300 W), slot width (dual-slot), power connectors (2x 8-pin), suggested PSU (700 W), ROP count (64), dimensions (267 mm, 111 mm), and display outputs (none). These are not listed in the section above because they are not differentiators.

FAQ

Q: Which card wins the Geekbench OpenCL benchmark?

A: The AMD Instinct MI100 wins. It scores 139,035 compared to the MI25’s 68,562, a delta of 102.8%.

Q: How does the MI100 compare to its nearest rivals?

A: The MI100 is 0.7% ahead of the NVIDIA Tesla V100 PCIe 16 GB, 0.9% ahead of the Tesla V100 SXM2 32 GB, 1.9% ahead of the AMD Radeon PRO V620, and 2.4% ahead of the AMD Radeon Pro W6800X Duo.

Q: How does the MI25 compare to its nearest rivals?

A: The MI25 is 0.4% behind the Intel Arc A770 and 0.6% behind the NVIDIA CMP 90HX, but it is 1.9% ahead of the AMD Radeon Pro WX 8200 and 2.0% ahead of the NVIDIA Quadro P6000.

Q: Does the MI25 support any graphics APIs?

A: Yes. The MI25 supports DirectX 12 (12_1), OpenGL 4.6, and Vulkan 1.3. The MI100 lists N/A for all three APIs.

Q: Which accelerator has more memory bandwidth?

A: The MI100 has 1.23 TB/s, while the MI25 has 436.2 GB/s. The MI100 also has double the memory capacity (32 GB vs 16 GB) and a wider bus (4096-bit vs 2048-bit).

Q: What is the manufacturing process difference?

A: The MI100 is built on TSMC’s 7 nm process, while the MI25 is built on GlobalFoundries’ 14 nm process. The MI100 has 25,600 million transistors on a 750 mm² die; the MI25 has 12,500 million on a 495 mm² die.