AMD Instinct MI300X vs NVIDIA H800 SXM5 Comparison

The Verdict

The data in the database presents a clear distinction between these two server accelerators. The AMD Instinct MI300X is positioned as a high-capacity compute solution with a recorded benchmark score, while the NVIDIA H800 SXM5 appears in the database with no benchmark scores and a lower percentile ranking. The MI300X delivers a Geekbench OpenCL score of 317,994, placing it in the 100th percentile of all GPUs, while the H800 SXM5 holds a 50th percentile ranking with an average benchmark score of zero. The MI300X is the only one of the two with measurable performance data, making it the choice for workloads where raw compute throughput in OpenCL is the primary selection criterion. The H800 SXM5, with its distinct memory configuration and tensor core count, serves a different segment, but the absence of benchmark data in the database prevents a quantitative comparison of its compute performance.

Architecture Differences

The architectural split between the two accelerators is significant. The AMD Instinct MI300X is built on the CDNA 3.0 architecture, using the Aqua Vanjaram chip, while the NVIDIA H800 SXM5 uses the Hopper architecture with the GH100 chip. Both are manufactured on a 5 nm process at TSMC, but the transistor counts diverge sharply. The MI300X contains 153,000 million transistors on a 1017 mm² die, yielding a transistor density of 150.4M per mm². The H800 SXM5 houses 80,000 million transistors on an 814 mm² die, resulting in a density of 98.3M per mm². This difference in density indicates a more densely packed design for the AMD part.

The memory subsystems are a major differentiator. The MI300X carries 192 GB of HBM3 memory on an 8192-bit bus, delivering 5.32 TB/s of bandwidth. The H800 SXM5 offers 80 GB of HBM3 memory on a 5120-bit bus, with 3.36 TB/s of bandwidth. The MI300X has nearly two and a half times the memory capacity and significantly higher bandwidth. The AMD part has 19,456 shading units and 1,216 texture mapping units, while the NVIDIA part has 16,896 shading units and 528 TMUs. The H800 SXM5 includes 528 tensor cores and 24 ROPs, whereas the MI300X has no listed ROPs and no tensor core count in the database. The MI300X reports a pixel rate of 0 MPixel/s and a texture rate of 2,553.6 GTexel/s, while the H800 SXM5 reports 42.12 GPixel/s and 926.6 GTexel/s.

Clock behavior also differs. The MI300X has a base clock of 1000 MHz and a boost clock of 2100 MHz, while the H800 SXM5 has a base of 1095 MHz and a boost of 1755 MHz. The memory clocks are close, with the MI300X at 1300 MHz (5.2 Gbps effective) and the H800 at 1313 MHz (5.3 Gbps effective). In terms of compute output, the MI300X achieves 81.72 TFLOPS for both FP32 and FP16 (at a 1:1 ratio), while the H800 SXM5 delivers 59.30 TFLOPS for FP32 and 237.2 TFLOPS for FP16 (at a 4:1 ratio). The H800 SXM5 has a higher FP16 throughput, but the MI300X leads in FP32.

The physical specifications differ as well. The MI300X is an OAM Module with no power connectors and a TDP of 750 W, while the H800 SXM5 is an SXM Module with an 8-pin EPS connector and a TDP of 700 W. The suggested PSU is 1150 W for the AMD part and 1100 W for the NVIDIA part. Both use a PCIe 5.0 x16 bus interface and have no display outputs. The MI300X was released on December 5, 2023, while the H800 SXM5 was released on March 20, 2023. The H800 SXM5 is marked as active production, with its predecessor listed as Server Ada and successor as Server Blackwell.

FAQ

Q: Which accelerator has more memory capacity?

A: The AMD Instinct MI300X has 192 GB of HBM3 memory, while the NVIDIA H800 SXM5 has 80 GB of HBM3 memory.

Q: What is the memory bandwidth difference?

A: The MI300X provides 5.32 TB/s of bandwidth on an 8192-bit bus, compared to 3.36 TB/s on a 5120-bit bus for the H800 SXM5.

Q: How do the FP32 performance figures compare?

A: The MI300X delivers 81.72 TFLOPS of FP32 performance, which is higher than the H800 SXM5's 59.30 TFLOPS.

Q: Which chip has a higher boost clock?

A: The MI300X has a boost clock of 2100 MHz, exceeding the H800 SXM5's boost clock of 1755 MHz.

Q: Are there any benchmark scores recorded for the H800 SXM5?

A: The database lists no benchmark scores for the H800 SXM5, with an average benchmark score of zero and no nearest rivals.

Q: What is the transistor density for each chip?

A: The MI300X has a transistor density of 150.4M per mm², while the H800 SXM5 has 98.3M per mm².

Specification Differences

The two accelerators differ across nearly every major specification field. The MI300X uses the Aqua Vanjaram chip with CDNA 3.0 architecture, while the H800 SXM5 uses the GH100 chip with Hopper architecture. The MI300X has 153,000 million transistors, compared to 80,000 million in the H800. The die size is 1017 mm² for the AMD part and 814 mm² for the NVIDIA part. Transistor density is 150.4M per mm² versus 98.3M per mm².

Clock speeds show a split: the MI300X runs at 1000 MHz base and 2100 MHz boost, while the H800 runs at 1095 MHz base and 1755 MHz boost. Memory clocks are nearly identical, with the MI300X at 1300 MHz (5.2 Gbps effective) and the H800 at 1313 MHz (5.3 Gbps effective). Memory capacity is 192 GB versus 80 GB, and bus width is 8192-bit versus 5120-bit. Bandwidth is 5.32 TB/s versus 3.36 TB/s.

Shading units are 19,456 on the MI300X and 16,896 on the H800. TMUs are 1,216 versus 528. ROPs are 0 on the MI300X and 24 on the H800. The H800 has 528 tensor cores, while the MI300X has no listed tensor core count. Pixel rate is 0 MPixel/s on the MI300X and 42.12 GPixel/s on the H800. Texture rate is 2,553.6 GTexel/s versus 926.6 GTexel/s. FP32 is 81.72 TFLOPS versus 59.30 TFLOPS. FP16 is 81.72 TFLOPS (1:1) versus 237.2 TFLOPS (4:1).

TDP is 750 W for the MI300X and 700 W for the H800. The form factor is OAM Module versus SXM Module. The power connector is none for the MI300X and 8-pin EPS for the H800. Suggested PSU is 1150 W versus 1100 W. Release dates are December 5, 2023, and March 20, 2023, respectively. The H800 has a production status of Active, while the MI300X has no listed status. The H800 lists a predecessor (Server Ada) and successor (Server Blackwell); the MI300X lists a predecessor (Radeon Instinct) but no successor.

Head-to-Head Benchmarks

The database records no direct head-to-head benchmark results between the AMD Instinct MI300X and the NVIDIA H800 SXM5. The head-to-head benchmark field is empty, and the wins tally is zero for both parts. However, the MI300X has a single benchmark entry: a Geekbench OpenCL score of 317,994. This score places it in the 100th percentile of all GPUs in the database. The H800 SXM5 has no benchmark entries, an average benchmark score of zero, and a 50th percentile ranking.

The MI300X's nearest rivals provide context for its performance. The NVIDIA H200 NVL has an average score of 334,891, which is 5% higher than the MI300X. The NVIDIA B200 has an average score of 345,482, 8% higher. The AMD part leads the NVIDIA L40S, which scores 295,763, by 7.5%. It also leads the NVIDIA RTX 6000 Ada Generation, which scores 287,237, by 10.7%. These deltas show the MI300X sitting in the middle of a competitive field, trailing the top-tier H200 NVL and B200 while clearly ahead of the L40S and RTX 6000 Ada.

The FP32 and FP16 figures from the specification data offer a separate performance view. The MI300X delivers 81.72 TFLOPS in both FP32 and FP16, indicating a 1:1 ratio. The H800 SXM5 delivers 59.30 TFLOPS in FP32 and 237.2 TFLOPS in FP16, a 4:1 ratio. For FP32-heavy workloads, the MI300X is ahead by 22.42 TFLOPS. For FP16-heavy workloads, the H800 SXM5 is ahead by 155.48 TFLOPS. No benchmark scores exist to confirm which architecture translates these raw figures into real-world application performance.

The texture and pixel rates also differ. The MI300X posts a texture rate of 2,553.6 GTexel/s, which is 1,627 GTexel/s higher than the H800's 926.6 GTexel/s. The H800 has a pixel rate of 42.12 GPixel/s, while the MI300X reports 0 MPixel/s, reflecting the absence of ROPs on the AMD part. These metrics indicate that the MI300X is optimized for texture-heavy compute tasks, while the H800 retains rasterization capabilities.

The memory bandwidth gap is substantial. The MI300X offers 5.32 TB/s, which is 1.96 TB/s more than the H800's 3.36 TB/s. Combined with the 192 GB capacity, the AMD part provides a larger memory pool for large model inference or data-intensive workloads. The H800's tensor core count of 528 suggests a focus on matrix operations, but without benchmark data, the database cannot confirm its practical advantage.

The percentile rankings reinforce the performance gap. The MI300X sits at the 100th percentile of all GPUs, while the H800 sits at the 50th percentile. The MI300X's average benchmark score of 317,994 contrasts with the H800's average of zero. The nearest rivals for the MI300X are all NVIDIA parts, which indicates that the competitive landscape is dominated by NVIDIA, with the AMD accelerator positioned between the L40S and the H200 NVL in the recorded scores. The H800 SXM5 has no listed rivals, leaving its relative performance undefined in the database.