AMD Instinct MI325X vs NVIDIA B300 SXM6 AC Comparison

Head-to-Head Benchmarks

The recorded database contains no direct head-to-head benchmark results between the AMD Instinct MI325X and the NVIDIA B300 SXM6 AC. The MI325X has no benchmark entries, while the B300 SXM6 AC has a single recorded score. This asymmetry means the comparison relies on the B300's measured performance and the architectural specifications of both accelerators.

The NVIDIA B300 SXM6 AC delivers a Geekbench OpenCL score of 369,831. This places it in the 100th percentile of all GPUs in the database, a top-tier position. Its nearest rivals provide context for this result. The B300 sits 7% ahead of the NVIDIA B200, which scores 345,482. It outperforms the NVIDIA H200 NVL by 10.4%, with that card scoring 334,891. Against the AMD Instinct MI300X, the B300 leads by 16.3%, as the MI300X records 317,994. The gap widens to 25% when compared to the NVIDIA L40S, which posts 295,763.

The MI325X has no recorded benchmark scores and an average score of zero. Its percentile versus all GPUs is recorded as 50, but without actual measurements, this reflects an unranked position rather than a competitive result. The data shows that the B300 SXM6 AC is the only one of the two with verified performance numbers, and those numbers position it firmly ahead of every named rival in the database.

FAQ

Q: Does the AMD Instinct MI325X have any benchmark scores in the database?

A: No. The MI325X has an empty benchmarks array, an average benchmark score of 0, and no nearest rivals listed. The NVIDIA B300 SXM6 AC, by contrast, has a Geekbench OpenCL score of 369,831.

Q: How far ahead is the NVIDIA B300 SXM6 AC of the AMD Instinct MI300X?

A: The B300 leads the MI300X by 16.3% in the recorded benchmark. The MI300X scores 317,994, while the B300 scores 369,831.

Q: What is the process node for both accelerators?

A: Both the AMD Instinct MI325X and the NVIDIA B300 SXM6 AC are fabricated on a 5 nm process at TSMC.

Q: Which accelerator has more memory bandwidth?

A: The NVIDIA B300 SXM6 AC has 8.19 TB/s of bandwidth, while the AMD Instinct MI325X has 6.14 TB/s. The B300 also has more memory capacity at 288 GB versus 256 GB.

Q: What is the power connector requirement for each card?

A: The AMD Instinct MI325X has no power connectors listed and a suggested PSU of 1400 W. The NVIDIA B300 SXM6 AC has no power connector data but a suggested PSU of 1500 W.

Q: Which card has the higher boost clock?

A: The NVIDIA B300 SXM6 AC boosts to 2032 MHz, while the AMD Instinct MI325X boosts to 2100 MHz. The MI325X has the higher boost clock despite having a lower base clock of 1000 MHz versus the B300's 1665 MHz.

Architecture Differences

The two accelerators come from different architectural lineages. AMD uses CDNA 3.0, built around the Aqua Vanjaram chip, part of the Instinct (MIx) generation. NVIDIA uses Blackwell Ultra, built around the GB110 chip, in the Server Blackwell (Bxx) generation. Both are fabricated on a 5 nm process at TSMC, but the transistor counts diverge significantly. The MI325X packs 153,000 million transistors on a 1017 mm² die, yielding a density of 150.4M transistors per mm². The B300 SXM6 AC carries 208,000 million transistors on a much larger 1628 mm² die, with a lower density of 127.8M per mm². The B300's larger die and higher transistor count indicate a more complex design, though the MI325X achieves higher packing density.

Memory architecture shows both similarity and difference. Both use HBM3e with an 8192-bit bus width. The MI325X has 256 GB of memory with 6.14 TB/s bandwidth. The B300 has 288 GB with 8.19 TB/s, a 32 GB capacity advantage and roughly one-third more bandwidth. The effective memory clock also differs: the MI325X runs at 1500 MHz (6 Gbps effective), while the B300 runs at 2000 MHz (8 Gbps effective).

Compute resources are organized differently. The MI325X has 19,456 shading units, 1,216 texture mapping units, and no ROPs. The B300 has 18,944 shading units, only 592 TMUs, and 24 ROPs. The MI325X has no tensor cores listed, while the B300 has 592 tensor cores. Neither card has ray tracing cores. The MI325X has no display outputs, and neither does the B300, which is expected for server accelerators.

The bus interface differs: the MI325X uses PCIe 5.0 x16, while the B300 uses PCIe 6.0 x16. This gives the B300 a newer interconnect standard. The MI325X reports a pixel rate of 0 MPixel/s, consistent with having no ROPs, while the B300 delivers 48.77 GPixel/s. Texture rates also differ substantially: the MI325X achieves 2,553.6 GTexel/s, more than double the B300's 1,202.9 GTexel/s. Floating-point performance is close: the MI325X delivers 81.72 TFLOPS in both FP32 and FP16 (1:1), while the B300 delivers 76.99 TFLOPS in both. The MI325X has a slight edge in raw FP throughput and a much larger lead in texture fill rate, while the B300 counters with tensor cores and ROP support.

Specification Differences

The following specifications differ between the two accelerators:

| Specification | AMD Instinct MI325X | NVIDIA B300 SXM6 AC |

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

| Architecture | CDNA 3.0 | Blackwell Ultra |

| Chip | Aqua Vanjaram | GB110 |

| Transistors | 153,000 million | 208,000 million |

| Die size | 1017 mm² | 1628 mm² |

| Transistor density | 150.4M / mm² | 127.8M / mm² |

| Base clock | 1000 MHz | 1665 MHz |

| Boost clock | 2100 MHz | 2032 MHz |

| Memory clock | 1500 MHz, 6 Gbps effective | 2000 MHz, 8 Gbps effective |

| Memory size | 256 GB | 288 GB |

| Memory bandwidth | 6.14 TB/s | 8.19 TB/s |

| Shading units | 19,456 | 18,944 |

| TMUs | 1,216 | 592 |

| ROPs | 0 | 24 |

| Tensor cores | None listed | 592 |

| Pixel rate | 0 MPixel/s | 48.77 GPixel/s |

| Texture rate | 2,553.6 GTexel/s | 1,202.9 GTexel/s |

| FP32 | 81.72 TFLOPS | 76.99 TFLOPS |

| FP16 | 81.72 TFLOPS (1:1) | 76.99 TFLOPS (1:1) |

| TDP | 1000 W | 1100 W |

| Slot width | OAM Module | SXM Module |

| Suggested PSU | 1400 W | 1500 W |

| Bus interface | PCIe 5.0 x16 | PCIe 6.0 x16 |

| Release date | 2024-10-09 | 2025-09-10 |

| Predecessor | Radeon Instinct | Server Hopper |

| Successor | None listed | Server Rubin |

| Production status | Not listed | Active |

The B300 is the newer part, released about eleven months after the MI325X. Its production status is active, while the MI325X has no status listed. The B300 also has a named successor in Server Rubin, while the MI325X lists none.

The Verdict

The data supports a clear verdict for the NVIDIA B300 SXM6 AC in measured performance. Its Geekbench OpenCL score of 369,831 places it at the 100th percentile, with double-digit percentage leads over multiple rivals. The AMD Instinct MI325X has no benchmark results, so its actual performance cannot be verified from the database. The B300 also offers more memory capacity (288 GB versus 256 GB), higher bandwidth (8.19 TB/s versus 6.14 TB/s), tensor cores, ROPs, a newer PCIe interface, and a higher base clock.

The MI325X counters with a higher boost clock (2100 MHz versus 2032 MHz), more shading units (19,456 versus 18,944), more TMUs (1,216 versus 592), a higher texture rate (2,553.6 GTexel/s versus 1,202.9 GTexel/s), and slightly higher FP32 and FP16 throughput (81.72 versus 76.99 TFLOPS). It also draws less power per the TDP figures, 1000 W versus 1100 W, and has a lower suggested PSU at 1400 W versus 1500 W.

For a decision based purely on verified performance, the B300 SXM6 AC is the only option with recorded results, and those results are strong. For a decision based on raw compute throughput and texture processing, the MI325X has a theoretical edge in those specific areas. The B300 is the newer design with an active production status and a successor already named.

Where Each One Wins

The NVIDIA B300 SXM6 AC wins in every measured benchmark category, since it is the only one with recorded scores. Its 369,831 Geekbench OpenCL result beats the nearest rival, the B200, by 7%, and extends to 16.3% over the AMD Instinct MI300X. The B300 also wins on memory capacity, bandwidth, tensor core availability, ROP count, pixel rate, base clock, bus interface generation, and production status.

The AMD Instinct MI325X wins on architectural features that favor raw throughput. It delivers 81.72 TFLOPS in FP32 and FP16, ahead of the B300's 76.99 TFLOPS. Its texture rate of 2,553.6 GTexel/s is more than double the B300's 1,202.9 GTexel/s. It has more shading units and TMUs. Its boost clock of 2100 MHz exceeds the B300's 2032 MHz. It also has a lower TDP and a lower suggested PSU requirement.

For workloads that depend on memory bandwidth and capacity, tensor operations, or the newer PCIe 6.0 interface, the B300 SXM6 AC is the stronger choice. For workloads that depend on FP32 throughput or texture fill rate, the MI325X has the theoretical advantage. The B300's measured benchmark dominance, however, gives it the overall edge in any comparison where actual performance matters more than paper specifications.