AMD Radeon Instinct MI300X vs NVIDIA H20 Comparison

FAQ

Q: What are the core architectural differences between the AMD Radeon Instinct MI300X and the NVIDIA H20?

A: The MI300X uses AMD's CDNA 3.0 architecture with the Aqua Vanjaram chip, while the H20 uses NVIDIA's Hopper architecture with the GH100 chip. Both are built on a 5 nm process at TSMC, but the MI300X packs 153,000 million transistors on a 1017 mm² die, compared to the H20's 80,000 million transistors on an 814 mm² die. The MI300X also has a higher transistor density at 150.4M per mm² versus 98.3M per mm² for the H20.

Q: How do their memory configurations compare?

A: The MI300X features 192 GB of HBM3 memory with an 8192-bit bus and 10.3 TB/s bandwidth. The H20 offers 96 GB of HBM3 memory with a 6144-bit bus and 4.03 TB/s bandwidth. The MI300X has double the capacity and over 2.5 times the bandwidth.

Q: What are the clock speed differences?

A: The H20 runs at a base clock of 1830 MHz and a boost clock of 1980 MHz. The MI300X has a lower base clock of 1000 MHz but a higher boost clock of 2100 MHz. The H20's memory runs at 1313 MHz (5.3 Gbps effective), while the MI300X's memory runs at 2525 MHz (10.1 Gbps effective).

Q: Which GPU has higher compute throughput?

A: The MI300X delivers 81.72 TFLOPS FP32 and 653.7 TFLOPS FP16 (8:1). The H20 provides 39.54 TFLOPS FP32 and 79.07 TFLOPS FP16 (2:1). The MI300X is roughly 2.1 times ahead in FP32 and over 8 times ahead in FP16 throughput as recorded.

Q: How do their power requirements differ?

A: The MI300X has a TDP of 750 W with a suggested PSU of 1150 W. The H20 has a TDP of 500 W with a suggested PSU of 900 W. The MI300X draws more power but also provides substantially higher compute performance.

Q: What form factors do they use?

A: The MI300X uses an OAM Module slot width, while the H20 uses an SXM Module slot width. Both connect via PCIe 5.0 x16 and have no display outputs.

Architecture Differences

The AMD Radeon Instinct MI300X and NVIDIA H20 diverge fundamentally in their compute architectures. The MI300X is built on AMD's CDNA 3.0 architecture, which is purpose-designed for data center compute workloads, focusing on raw throughput. The H20 uses NVIDIA's Hopper architecture, which emphasizes a balance of compute and specialized tensor operations.

The transistor counts tell a clear story: the MI300X integrates 153,000 million transistors, nearly double the H20's 80,000 million. This translates to a die size of 1017 mm² for the MI300X versus 814 mm² for the H20. The transistor density also differs: 150.4M per mm² for the MI300X versus 98.3M per mm² for the H20. This higher density suggests a more tightly packed design, likely reflecting the MI300X's larger memory bus and compute array.

The MI300X has 19,456 shading units and 1,216 texture mapping units, while the H20 has 9,984 shading units and 312 texture mapping units. The H20 does have 24 ROPs compared to the MI300X's 0 ROPs, and the MI300X has no reported ROP count, indicating its design prioritizes compute over rasterization. The H20 also includes 312 tensor cores, while the MI300X's tensor core count is not specified in the data.

The memory subsystems are a major architectural differentiator. The MI300X's 8192-bit bus is exceptionally wide, enabling 10.3 TB/s bandwidth with 192 GB of HBM3. The H20's 6144-bit bus provides 4.03 TB/s with 96 GB of HBM3. The MI300X's memory clock runs at 2525 MHz (10.1 Gbps effective), while the H20's runs at 1313 MHz (5.3 Gbps effective). These numbers indicate the MI300X is engineered for massive memory throughput, which is critical for large model inference and training.

The MI300X has no pixel rate recorded (0 MPixel/s), while the H20 has a pixel rate of 47.52 GPixel/s. The MI300X's texture rate is 2,553.6 GTexel/s, far exceeding the H20's 617.8 GTexel/s. This further confirms the MI300X's focus on compute and memory bandwidth rather than graphics output.

The Verdict

The recorded data indicates a clear performance hierarchy. The AMD Radeon Instinct MI300X outperforms the NVIDIA H20 in nearly every compute and memory metric. For FP32 workloads, the MI300X delivers 81.72 TFLOPS versus 39.54 TFLOPS for the H20, a 2.1 times advantage. For FP16, the MI300X's 653.7 TFLOPS dwarfs the H20's 79.07 TFLOPS, an 8.3 times advantage.

The memory specifications reinforce this verdict. The MI300X's 192 GB capacity is exactly double the H20's 96 GB, and its 10.3 TB/s bandwidth is roughly 2.6 times the H20's 4.03 TB/s. This makes the MI300X the superior choice for workloads that require large memory footprints and high bandwidth, such as training large language models or processing massive datasets.

The H20 does have advantages in certain areas. Its pixel rate of 47.52 GPixel/s is nonzero, whereas the MI300X has a 0 MPixel/s pixel rate, suggesting the H20 retains some graphics capability. The H20 also has a higher base clock (1830 MHz versus 1000 MHz) and a lower TDP (500 W versus 750 W), which may be relevant for power-constrained deployments.

However, for data center compute, the MI300X's raw performance metrics dominate. Users requiring maximum FP32 or FP16 throughput, larger memory capacity, or higher memory bandwidth should select the MI300X. Users prioritizing lower power consumption or needing some graphics output capability may consider the H20, but the performance gap is substantial.

Specification Differences

| Specification | AMD Radeon Instinct MI300X | NVIDIA H20 |

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

| Architecture | CDNA 3.0 | Hopper |

| Chip | Aqua Vanjaram | GH100 |

| Transistors | 153,000 million | 80,000 million |

| Die Size | 1017 mm² | 814 mm² |

| Transistor Density | 150.4M / mm² | 98.3M / mm² |

| Base Clock | 1000 MHz | 1830 MHz |

| Boost Clock | 2100 MHz | 1980 MHz |

| Memory Clock | 2525 MHz (10.1 Gbps effective) | 1313 MHz (5.3 Gbps effective) |

| Memory Size | 192 GB | 96 GB |

| Memory Type | HBM3 | HBM3 |

| Memory Bus Width | 8192 bit | 6144 bit |

| Memory Bandwidth | 10.3 TB/s | 4.03 TB/s |

| Shading Units | 19,456 | 9,984 |

| TMUs | 1,216 | 312 |

| ROPs | 0 | 24 |

| Tensor Cores | Not specified | 312 |

| Pixel Rate | 0 MPixel/s | 47.52 GPixel/s |

| Texture Rate | 2,553.6 GTexel/s | 617.8 GTexel/s |

| FP32 | 81.72 TFLOPS | 39.54 TFLOPS |

| FP16 | 653.7 TFLOPS (8:1) | 79.07 TFLOPS (2:1) |

| TDP | 750 W | 500 W |

| Slot Width | OAM Module | SXM Module |

| Suggested PSU | 1150 W | 900 W |

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

| Display Outputs | No outputs | No outputs |

| Release Date | 2023-12-05 | 2024-01-31 |

| Production Status | Not specified | Active |

Head-to-Head Benchmarks

The recorded data provides a direct comparison across multiple compute metrics. The most striking difference is in FP16 performance. The MI300X achieves 653.7 TFLOPS, while the H20 delivers 79.07 TFLOPS. This represents an 8.3 times advantage for the MI300X. The FP16 ratio also differs: the MI300X uses an 8:1 ratio, while the H20 uses a 2:1 ratio, indicating different precision handling strategies.

In FP32, the MI300X records 81.72 TFLOPS versus 39.54 TFLOPS for the H20. This is a 2.1 times lead for the MI300X, which is significant for workloads that rely on single-precision floating-point operations.

Memory bandwidth is another decisive metric. The MI300X's 10.3 TB/s is 2.6 times the H20's 4.03 TB/s. The memory capacity difference is exactly double: 192 GB versus 96 GB. These figures suggest that the MI300X can handle much larger batch sizes or more complex models without hitting memory bottlenecks.

Texture rate also favors the MI300X dramatically: 2,553.6 GTexel/s versus 617.8 GTexel/s, a 4.1 times advantage. This indicates the MI300X's compute pipeline is substantially more efficient at processing texture-like data, which is relevant for certain scientific computing tasks.

The H20 does win on pixel rate: 47.52 GPixel/s versus 0 MPixel/s for the MI300X. This is the only metric where the H20 has a nonzero value and the MI300X has zero, suggesting the H20 retains some graphics output capability that the MI300X lacks entirely.

The H20 also has a higher base clock: 1830 MHz versus 1000 MHz for the MI300X. However, the MI300X's boost clock of 2100 MHz exceeds the H20's 1980 MHz, indicating the MI300X can reach higher peak performance under load.

Where Each One Wins

The AMD Radeon Instinct MI300X wins decisively in compute-heavy workloads. Its FP32 throughput of 81.72 TFLOPS makes it suitable for scientific simulations, financial modeling, and any application relying on single-precision calculations. Its FP16 output of 653.7 TFLOPS positions it as a strong candidate for AI training and inference, particularly for large models that benefit from the 192 GB memory capacity and 10.3 TB/s bandwidth.

The MI300X also excels in memory-bound tasks. The 8192-bit bus and 192 GB capacity allow it to handle datasets that would exceed the H20's 96 GB limit. This is critical for tasks like training deep neural networks with large embedding tables or processing high-resolution volumetric data.

The NVIDIA H20 wins in scenarios where power consumption is a primary constraint. Its 500 W TDP is 250 W lower than the MI300X's 750 W, and its suggested PSU of 900 W is lower than the MI300X's 1150 W. For data centers with strict power budgets, this could be a deciding factor.

The H20 also maintains a nonzero pixel rate of 47.52 GPixel/s, making it the only one of the two with any graphics processing capability. While neither card has display outputs, the H20's ROPs and pixel pipeline could be useful for workloads that require some rasterization, such as certain visualization tasks.

The H20's higher base clock of 1830 MHz suggests it may have better sustained performance at lower utilization levels, though the MI300X's higher boost clock of 2100 MHz indicates it can reach higher peak performance. The H20 also has 312 tensor cores, which are not specified for the MI300X, potentially giving it an edge in tensor-focused operations, though the MI300X's overall FP16 advantage suggests it may still be faster in practice.

For users prioritizing maximum compute throughput, memory capacity, and bandwidth, the MI300X is the clear choice. For users prioritizing lower power draw and retaining any graphics capability, the H20 offers a more modest but more power-efficient profile.