NVIDIA B300 SXM6 AC vs NVIDIA H100 CNX Comparison

The Verdict

The recorded data positions the NVIDIA B300 SXM6 AC as the clear performance leader, with a Geekbench OpenCL score of 369,831 placing it in the 100th percentile of all GPUs. Its nearest rival, the NVIDIA B200, scores 345,482, which is 7% behind. The H100 CNX has no recorded benchmark scores in the database, and its average benchmark score is listed as 0, placing it in the 50th percentile. For workloads that rely on raw compute throughput, memory capacity, and bandwidth, the B300 SXM6 AC is the only option with measurable data. The H100 CNX uses an older architecture, a smaller memory pool, and lower clock speeds, but its lower power draw and dual-slot form factor make it a more physically accommodating part for systems with space and power constraints.

Architecture Differences

The B300 SXM6 AC is built on the Blackwell Ultra architecture with the GB110 chip, while the H100 CNX uses the Hopper architecture with the GH100 chip. Both are fabricated on a 5 nm process at TSMC, but the B300 packs 208,000 million transistors on a 1628 mm² die, giving a transistor density of 127.8M per mm². The H100 CNX has 80,000 million transistors on an 814 mm² die, with a density of 98.3M per mm². The B300's transistor count is 2.6 times higher, and its die is exactly twice the area.

The B300 SXM6 AC uses HBM3e memory, while the H100 CNX uses HBM2e. The B300's memory bus is 8192 bit wide, compared to 5120 bit on the H100. The B300 has 592 tensor cores and 18,944 shading units, while the H100 has 456 tensor cores and 14,592 shading units. Both have 24 ROPs, but the B300 has 592 TMUs versus 456 on the H100. The B300 supports PCIe 6.0 x16, and the H100 uses PCIe 5.0 x16. Neither part has display outputs, and both have no API support for DirectX, OpenGL, or Vulkan in the database.

The B300's base clock is 1665 MHz with a boost of 2032 MHz, while the H100 runs at a 690 MHz base and 1845 MHz boost. The B300's FP32 throughput is 76.99 TFLOPS and its FP16 is 76.99 TFLOPS at a 1:1 ratio, while the H100's FP32 is 53.84 TFLOPS and its FP16 is 215.4 TFLOPS at a 4:1 ratio. This means the H100 delivers more than double the FP16 compute per cycle when using its 4:1 path, but the B300's higher clocks and larger core count make its FP32 output 43% higher.

Head-to-Head Benchmarks

The head-to-head benchmark list is empty, and the win counts for both parts are zero. The only recorded score belongs to the B300 SXM6 AC: 369,831 in Geekbench OpenCL. That score sits 7% above the NVIDIA B200's 345,482, 10.4% above the H200 NVL's 334,891, 16.3% above the AMD Instinct MI300X's 317,994, and 25% above the L40S's 295,763. The B300's 100th percentile ranking means no other GPU in the database scores higher in this test.

The H100 CNX has no benchmark entries, so no direct comparison is possible. Its average benchmark score is recorded as 0, and its percentile is 50, which indicates it sits at the median of all GPUs based on whatever data the database holds, but that median is not tied to any measured score. Without a score, the only reliable comparison is architectural: the B300 has 128.8% more shading units, 29.8% more tensor cores, and 260% more memory bandwidth. The B300's FP32 rate is 43% higher, and its pixel rate is 48.77 GPixel/s versus 44.28 GPixel/s on the H100. The texture rate is 1,202.9 GTexel/s on the B300 versus 841.3 GTexel/s on the H100, a 43% difference. The B300's memory bandwidth advantage is even larger: 8.19 TB/s versus 2.04 TB/s, a 301% gap.

FAQ

Q: Which GPU has the higher recorded benchmark score?

A: The B300 SXM6 AC has a Geekbench OpenCL score of 369,831, which is the 100th percentile. The H100 CNX has no recorded benchmark scores in the database.

Q: How does the B300 compare to its nearest rivals?

A: The B300 is 7% ahead of the NVIDIA B200, 10.4% ahead of the H200 NVL, 16.3% ahead of the AMD Instinct MI300X, and 25% ahead of the L40S in average benchmark score.

Q: What is the memory configuration difference?

A: The B300 uses 288 GB of HBM3e on a 8192 bit bus with 8.19 TB/s bandwidth. The H100 CNX uses 80 GB of HBM2e on a 5120 bit bus with 2.04 TB/s bandwidth.

Q: Which GPU has a higher FP16 compute rate?

A: The H100 CNX lists FP16 at 215.4 TFLOPS with a 4:1 ratio, while the B300 lists FP16 at 76.99 TFLOPS with a 1:1 ratio. The H100's FP16 figure is 2.8 times higher, but the B300's 1:1 ratio means it does not trade off FP32 performance to reach that number.

Q: What are the power requirements?

A: The B300 has a TDP of 1100 W and a suggested PSU of 1500 W. The H100 CNX has a TDP of 350 W and a suggested PSU of 750 W.

Q: What are the physical form factors?

A: The B300 is a SXM Module, while the H100 CNX is a dual-slot card with a length of 267 mm (10.5 inches) and a height of 111 mm (4.4 inches).

Where Each One Wins

The B300 SXM6 AC wins on every recorded performance metric. Its Geekbench OpenCL score of 369,831 is the highest in the database, and it leads all nearest rivals by double-digit percentages in most cases. It has 3.6 times the memory capacity, 4 times the bandwidth, and 2.6 times the transistor count. For compute-heavy tasks like large model training, high-resolution inference, or data center workloads that need maximal FP32 throughput, the B300 is the clear choice. Its 1:1 FP16 ratio also means it can maintain full FP32 performance while offering FP16 compute at the same rate, which is useful for mixed-precision workloads that do not rely on the 4:1 throughput boost.

The H100 CNX wins on power efficiency and physical integration. Its 350 W TDP is 68% lower than the B300's 1100 W, and its suggested PSU of 750 W is half of the B300's 1500 W. The dual-slot form factor with a 267 mm length fits standard server chassis, while the SXM Module requires a specialized carrier board. The H100 also has a higher FP16 compute rate at 215.4 TFLOPS, which is 2.8 times the B300's FP16 figure, so for workloads that are heavily FP16-bound and can tolerate the lower FP32 throughput, the H100 may still be relevant. Its 80 GB of HBM2e is smaller but sufficient for mid-sized models.

Specification Differences

| Field | NVIDIA B300 SXM6 AC | NVIDIA H100 CNX |

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

| Chip | GB110 | GH100 |

| Architecture | Blackwell Ultra | Hopper |

| Process node | 5 nm | 5 nm |

| Transistors | 208,000 million | 80,000 million |

| Die size | 1628 mm² | 814 mm² |

| Transistor density | 127.8M / mm² | 98.3M / mm² |

| Base clock | 1665 MHz | 690 MHz |

| Boost clock | 2032 MHz | 1845 MHz |

| Memory size | 288 GB | 80 GB |

| Memory type | HBM3e | HBM2e |

| Memory bus | 8192 bit | 5120 bit |

| Memory bandwidth | 8.19 TB/s | 2.04 TB/s |

| Shading units | 18944 | 14592 |

| TMUs | 592 | 456 |

| ROPs | 24 | 24 |

| Tensor cores | 592 | 456 |

| FP32 | 76.99 TFLOPS | 53.84 TFLOPS |

| FP16 | 76.99 TFLOPS (1:1) | 215.4 TFLOPS (4:1) |

| Pixel rate | 48.77 GPixel/s | 44.28 GPixel/s |

| Texture rate | 1,202.9 GTexel/s | 841.3 GTexel/s |

| TDP | 1100 W | 350 W |

| Slot width | SXM Module | Dual-slot |

| Power connectors | None listed | 8-pin EPS |

| Suggested PSU | 1500 W | 750 W |

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

| Dimensions | Not listed | 267 mm (10.5 in) length, 111 mm (4.4 in) height |

| Release date | 2025-09-10 | 2023-03-20 |

| Predecessor | Server Hopper | Server Ada |

| Successor | Server Rubin | Server Blackwell |

The B300 is newer, larger, and faster in every measured compute category except FP16 peak. The H100 is older, smaller, and more power-efficient. The database shows no benchmark score for the H100, so its 50th percentile ranking is based on the aggregate of unlisted data rather than a direct measurement. The B300's 100th percentile is backed by a specific OpenCL score and a clear margin over all four nearest rivals.