AMD Instinct MI355X vs NVIDIA H100 PCIe 96 GB Comparison

FAQ

Q: What are the core specifications of the AMD Instinct MI355X?

A: The AMD Instinct MI355X uses the MI350 256CU chip based on CDNA 4.0 architecture, built on a 3 nm process at TSMC. It contains 185,000 million transistors on a 2380 mm² die, with 16,384 shading units, 1,024 TMUs, and a boost clock of 2400 MHz. The card features 288 GB of HBM3e memory on an 8192-bit bus, delivering 8.19 TB/s of bandwidth.

Q: What are the core specifications of the NVIDIA H100 PCIe 96 GB?

A: The NVIDIA H100 PCIe 96 GB uses the GH100 chip based on Hopper architecture, built on a 5 nm process at TSMC. It contains 80,000 million transistors on an 814 mm² die, with 16,896 shading units, 528 TMUs, 24 ROPs, and 528 tensor cores. The boost clock is 1837 MHz. Memory is 96 GB of HBM3 on a 5120-bit bus, providing 3.36 TB/s of bandwidth.

Q: How do the two cards compare in raw FP32 compute?

A: The AMD Instinct MI355X delivers 78.64 TFLOPS of FP32 performance, which is ahead of the NVIDIA H100 PCIe 96 GB's 62.08 TFLOPS. The AMD card's FP16 performance is also 78.64 TFLOPS with a 1:1 ratio, while the NVIDIA card reaches 248.3 TFLOPS FP16 with a 4:1 ratio.

Q: What are the power requirements for each card?

A: The AMD Instinct MI355X has a TDP of 1400 W and suggests an 1800 W power supply. The NVIDIA H100 PCIe 96 GB has a TDP of 700 W with a suggested 1100 W power supply. The NVIDIA card uses an 8-pin EPS power connector, while the AMD card lists no power connectors, as it is an OAM module.

Q: What are the physical differences between the two cards?

A: The AMD Instinct MI355X is an OAM module measuring 102 mm in length and 165 mm in width. The NVIDIA H100 PCIe 96 GB is a dual-slot card measuring 268 mm in length and 111 mm in height, using a PCIe 5.0 x16 interface. Both cards have no display outputs.

Q: When were these cards released, and what is their production status?

A: The AMD Instinct MI355X was released on 2025-06-11, while the NVIDIA H100 PCIe 96 GB was released on 2023-03-20. The NVIDIA card has a production status of "Active," while the AMD card's production status is not recorded in the database.

The Verdict

The recorded data shows two accelerators designed for different segments of the compute market. The AMD Instinct MI355X targets workloads that demand massive memory capacity and bandwidth. Its 288 GB of HBM3e and 8.19 TB/s bandwidth dwarf the NVIDIA H100 PCIe 96 GB's 96 GB of HBM3 and 3.36 TB/s. For models or datasets that exceed the NVIDIA card's memory ceiling, the AMD card is the only choice between these two.

The NVIDIA H100 PCIe 96 GB balances lower power draw with higher FP16 throughput. Its 248.3 TFLOPS FP16 (4:1) exceeds the AMD card's 78.64 TFLOPS FP16 (1:1) by a wide margin. The NVIDIA card also has a much lower TDP at 700 W versus 1400 W, and it fits in a standard dual-slot PCIe form factor. The AMD card's OAM module form factor requires a different system design.

For FP32-heavy workloads, the AMD card leads with 78.64 TFLOPS versus 62.08 TFLOPS. The NVIDIA card's 528 tensor cores and 4:1 FP16 ratio indicate a design optimized for mixed-precision training, while the AMD card's 1:1 FP16 ratio suggests a focus on FP32 compute with memory capacity as the primary advantage.

Head-to-Head Benchmarks

The database contains no recorded head-to-head benchmark scores for these two accelerators. Both cards show zero benchmark entries, zero wins for either side, and an identical percentile rank of 50 against all GPUs. The comparison must therefore rely entirely on the specification-level data recorded in the database.

The largest numerical advantage for the AMD Instinct MI355X is in memory bandwidth. At 8.19 TB/s, it delivers more than double the 3.36 TB/s of the NVIDIA H100 PCIe 96 GB. Memory capacity follows the same pattern: 288 GB versus 96 GB, a 3x difference. Texture rate also favors the AMD card at 2,457.6 GTexel/s versus 969.9 GTexel/s.

The NVIDIA H100 PCIe 96 GB holds its largest advantage in FP16 compute. At 248.3 TFLOPS, it is roughly 3.2x the AMD card's 78.64 TFLOPS. The NVIDIA card also has a higher base clock (1665 MHz versus 1000 MHz) and a higher transistor density (98.3M per mm² versus 77.7M per mm²), despite the AMD card having more total transistors.

FP32 performance favors the AMD card by 16.56 TFLOPS (78.64 versus 62.08). The AMD card also has nearly double the TMU count (1,024 versus 528), while the NVIDIA card has more shading units (16,896 versus 16,384) and includes 24 ROPs against the AMD card's zero recorded ROPs. The NVIDIA card has a pixel rate of 44.09 GPixel/s, while the AMD card records 0 MPixel/s.

Specification Differences

The two cards differ across nearly every recorded specification. Process node: the AMD card uses 3 nm, the NVIDIA card uses 5 nm, both at TSMC. Transistor count: 185,000 million for AMD versus 80,000 million for NVIDIA. Die size: 2380 mm² for AMD versus 814 mm² for NVIDIA. Transistor density: 77.7M per mm² for AMD versus 98.3M per mm² for NVIDIA.

Clock speeds differ substantially. The AMD card has a base clock of 1000 MHz and a boost clock of 2400 MHz. The NVIDIA card has a base clock of 1665 MHz and a boost clock of 1837 MHz. Memory clocks: 2000 MHz (8 Gbps effective) for AMD versus 1313 MHz (5.3 Gbps effective) for NVIDIA.

Memory configuration: 288 GB HBM3e on an 8192-bit bus for AMD versus 96 GB HBM3 on a 5120-bit bus for NVIDIA. Bandwidth: 8.19 TB/s versus 3.36 TB/s.

Compute units: AMD has 16,384 shading units, 1,024 TMUs, and zero ROPs. NVIDIA has 16,896 shading units, 528 TMUs, 24 ROPs, and 528 tensor cores. The AMD card records no tensor core count.

Output rates: AMD records 0 MPixel/s pixel rate and 2,457.6 GTexel/s texture rate. NVIDIA records 44.09 GPixel/s pixel rate and 969.9 GTexel/s texture rate.

Power and physical specs: AMD has a 1400 W TDP, is an OAM module, has no power connectors, and suggests an 1800 W PSU. NVIDIA has a 700 W TDP, is a dual-slot card, uses an 8-pin EPS connector, and suggests a 1100 W PSU. AMD dimensions: 102 mm length, 165 mm width. NVIDIA dimensions: 268 mm length, 111 mm height.

Release dates: AMD on 2025-06-11, NVIDIA on 2023-03-20. The NVIDIA card's predecessor is listed as Server Ada and its successor as Server Blackwell. The AMD card's predecessor is Radeon Instinct. The AMD card is in the Instinct (MIx) generation, while the NVIDIA card is in the Server Hopper (Hxx) generation. Both use PCIe 5.0 x16 and have no display outputs.

Architecture Differences

The AMD Instinct MI355X is built on CDNA 4.0 architecture, a design focused on compute acceleration with no display outputs and no recorded graphics API support (DirectX, OpenGL, and Vulkan all listed as N/A). The chip is the MI350 256CU, fabricated on a 3 nm process. The architecture records FP16 at a 1:1 ratio with FP32, meaning both formats deliver 78.64 TFLOPS. This indicates a design that does not double-rate FP16 operations.

The NVIDIA H100 PCIe 96 GB uses Hopper architecture with the GH100 chip on a 5 nm process. The architecture includes 528 tensor cores, which are dedicated matrix math units. The FP16 figure of 248.3 TFLOPS is recorded at a 4:1 ratio, meaning the tensor cores accelerate FP16 to four times the FP32 rate. The NVIDIA card also includes 24 ROPs and a pixel rate of 44.09 GPixel/s, features absent from the AMD card's recorded data.

Memory architecture differs in type and scale. The AMD card uses HBM3e with a wider 8192-bit bus, while the NVIDIA card uses HBM3 with a 5120-bit bus. The AMD card's 288 GB capacity at 8.19 TB/s positions it for memory-bound workloads. The NVIDIA card's smaller 96 GB pool at 3.36 TB/s is paired with higher FP16 throughput, suiting compute-bound mixed-precision tasks.

The transistor density figures reflect different design approaches. The AMD card packs 185,000 million transistors into 2380 mm² for a density of 77.7M per mm². The NVIDIA card packs 80,000 million transistors into 814 mm² for a density of 98.3M per mm². The NVIDIA die is more transistor-dense despite using a larger 5 nm process, while the AMD die uses a smaller 3 nm process with a much larger physical area.

Where Each One Wins

The AMD Instinct MI355X wins in scenarios where memory capacity and bandwidth are the limiting factors. The 288 GB HBM3e pool with 8.19 TB/s bandwidth supports models or batch sizes that cannot fit in 96 GB. The FP32 advantage (78.64 TFLOPS versus 62.08 TFLOPS) also favors the AMD card for single-precision workloads. The texture rate of 2,457.6 GTexel/s, more than double the NVIDIA card's 969.9 GTexel/s, indicates higher throughput for texture-heavy operations, though this is a compute card without display outputs.

The NVIDIA H100 PCIe 96 GB wins in FP16 and mixed-precision compute. The 248.3 TFLOPS FP16 figure is over three times the AMD card's 78.64 TFLOPS. The 528 tensor cores provide dedicated hardware for matrix operations. The lower 700 W TDP and standard dual-slot PCIe form factor make it adaptable to existing server infrastructure, while the AMD card's OAM module and 1400 W TDP require a different physical and power design.

The NVIDIA card also has a higher base clock (1665 MHz versus 1000 MHz) and a higher transistor density (98.3M per mm² versus 77.7M per mm²). The AMD card's boost clock of 2400 MHz exceeds the NVIDIA card's 1837 MHz. The AMD card's larger die and transistor count (185,000 million versus 80,000 million) reflect a physically larger processor, but the NVIDIA card achieves higher density on a smaller die.

For deployment in existing PCIe-based servers, the NVIDIA H100 PCIe 96 GB fits a dual-slot PCIe 5.0 x16 slot with a standard 8-pin EPS connector. The AMD card's OAM module form factor, 102 mm length, and 165 mm width, along with its 1800 W suggested PSU, indicate a system designed specifically around this accelerator. The data shows two distinct use cases: the AMD card for maximum memory capacity and FP32 throughput, and the NVIDIA card for FP16 performance in a lower-power, standard-form-factor package.