AMD Instinct MI455X vs NVIDIA RTX 4000 SFF Ada Generation Comparison

Head-to-Head Benchmarks

The database contains no direct head-to-head benchmark results between the AMD Instinct MI455X and the NVIDIA RTX 4000 SFF Ada Generation. The MI455X has an average benchmark score of 0, with no recorded tests, while the RTX 4000 SFF Ada Generation shows two recorded benchmark results. On Geekbench OpenCL, the NVIDIA card scores 124,812, and on Geekbench Vulkan, it scores 109,364. Its average benchmark score across these tests is 117,088.

The absence of benchmark data for the MI455X means a direct numerical comparison is not possible from the recorded measurements. The MI455X sits at the 50th percentile among all GPUs in the database, while the RTX 4000 SFF Ada Generation sits at the 95th percentile. This percentile gap is substantial, but it reflects the lack of test data for the AMD part rather than a measured performance deficit.

For the RTX 4000 SFF Ada Generation, the nearest rivals in the database provide context. The NVIDIA GB10 averages 117,393, which is 0.3% higher than the RTX 4000 SFF. The AMD Radeon PRO W7700 averages 118,976, which is 1.6% higher. The NVIDIA Tesla V100 SXM2 16 GB averages 114,395, which is 2.4% lower. The NVIDIA RTX A5500 Mobile averages 113,944, which is 2.8% lower. These deltas indicate the RTX 4000 SFF sits in a competitive band, slightly behind the GB10 and PRO W7700, while ahead of the Tesla V100 and RTX A5500 Mobile.

Where Each One Wins

Without benchmark data for the MI455X, the wins must be derived from the specification differences. The MI455X delivers substantially higher raw compute throughput. Its FP32 performance is 157.3 TFLOPS, and FP16 performance matches at 157.3 TFLOPS (1:1). Texture rate is 2,457.6 GTexel/s. These figures dwarf the RTX 4000 SFF Ada Generation, which delivers 19.17 TFLOPS FP32 and 19.17 TFLOPS FP16 (1:1), with a texture rate of 299.5 GTexel/s. The MI455X offers roughly 8.2 times the FP32 throughput, which indicates a clear advantage in compute-heavy workloads such as large-scale matrix operations or dense floating-point calculations.

Memory capacity strongly favors the MI455X. It has 432 GB of HBM4 memory on a 24,576-bit bus, yielding 23.3 TB/s of bandwidth. The RTX 4000 SFF has 20 GB of GDDR6 on a 160-bit bus, yielding 280.0 GB/s. The MI455X provides more than 21 times the memory capacity and more than 83 times the memory bandwidth. For workloads that require large in-memory datasets or high-bandwidth data movement, the MI455X is the clear winner.

The RTX 4000 SFF Ada Generation wins in areas where the MI455X has no capability. The NVIDIA card has 48 RT cores and 192 tensor cores, while the MI455X lists no RT cores and no tensor cores. The RTX 4000 SFF delivers a pixel rate of 99.84 GPixel/s, while the MI455X delivers 0 MPixel/s. The NVIDIA card has 4x mini-DisplayPort 1.4a outputs, while the MI455X has no display outputs. The RTX 4000 SFF also supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4, while the MI455X lists N/A for all three APIs. For graphics rendering, ray tracing, tensor operations, or any display output, the RTX 4000 SFF is the only option.

Power consumption shifts the use case picture. The MI455X has a TDP of 2300 W with a suggested PSU of 2700 W, while the RTX 4000 SFF has a TDP of 70 W with a suggested PSU of 250 W. The NVIDIA card consumes roughly 3% of the AMD card's power budget. For environments with strict power limits or dense multi-GPU installations, the RTX 4000 SFF is far more practical. The MI455X has no power connectors listed, and its slot width is described as "EAM Module," indicating a specialized form factor, while the RTX 4000 SFF is a dual-slot card.

Architecture Differences

The two GPUs come from different architectural generations and target different segments. The AMD Instinct MI455X uses the CDNA 5.0 architecture, built on a 2 nm process at TSMC, with the chip designated as "MI450 256CU." The NVIDIA RTX 4000 SFF Ada Generation uses the Ada Lovelace architecture, built on a 5 nm process at TSMC, with the AD104 chip. The process node difference is significant: 2 nm versus 5 nm, which generally indicates a newer manufacturing technology for the AMD part.

Transistor counts differ by an order of magnitude. The MI455X contains 320,000 million transistors (320 billion) on a die size of 2,990 mm², giving a transistor density of 107.0 million per mm². The RTX 4000 SFF contains 35,800 million transistors (35.8 billion) on a die size of 294 mm², giving a transistor density of 121.8 million per mm². The MI455X die is roughly 10.2 times larger, but the NVIDIA chip achieves a higher transistor density, indicating a more compact layout per area.

The MI455X uses 32,768 shading units and 1,024 TMUs, with no ROPs listed. The RTX 4000 SFF uses 6,144 shading units, 192 TMUs, and 64 ROPs. The AMD part has more than 5 times the shading units and more than 5 times the TMUs. The RTX 4000 SFF has dedicated RT cores and tensor cores, while the MI455X has none. The MI455X lists a pixel rate of 0 MPixel/s, consistent with a compute-focused accelerator that lacks a traditional rasterization pipeline.

Memory architecture diverges completely. The MI455X uses HBM4, a high-bandwidth stacked memory type, while the RTX 4000 SFF uses GDDR6, a conventional discrete memory type. The MI455X's 24,576-bit bus is 153.6 times wider than the RTX 4000 SFF's 160-bit bus. Effective memory speeds are listed as 7.6 Gbps for the MI455X and 14 Gbps for the RTX 4000 SFF, but the bus width difference dominates the bandwidth calculation.

The bus interface also differs. The MI455X uses PCIe 6.0 x16, while the RTX 4000 SFF uses PCIe 4.0 x16. The MI455X has a base clock of 1000 MHz and a boost clock of 2400 MHz, while the RTX 4000 SFF has a base clock of 720 MHz and a boost clock of 1560 MHz. Release dates are far apart: the MI455X is dated 2026-07-22, while the RTX 4000 SFF is dated 2023-03-20. The predecessor fields differ as well: the MI455X lists "Radeon Instinct" as its predecessor, while the RTX 4000 SFF lists "Workstation Ampere," and its successor is "Blackwell PRO W." The RTX 4000 SFF has a production status of "Active," while the MI455X has no production status listed.

The Verdict

The data shows two GPUs built for entirely different purposes. The AMD Instinct MI455X is a compute accelerator with massive FP32 throughput, enormous memory capacity, and extreme power requirements. The NVIDIA RTX 4000 SFF Ada Generation is a workstation graphics card with display outputs, ray tracing, tensor cores, and a modest power envelope. Neither card can substitute for the other in their primary roles.

For pure compute density, the MI455X is the stronger choice based on specifications. Its 157.3 TFLOPS FP32, 432 GB memory, and 23.3 TB/s bandwidth are far beyond what the RTX 4000 SFF can offer. The 2 nm process node and 320,000 million transistors indicate a state-of-the-art accelerator designed for large-scale data processing. However, the 2300 W TDP and suggested 2700 W PSU mean deployment requires specialized infrastructure. The lack of benchmark scores and the 50th percentile ranking leave its real-world performance unverified in the database.

For graphics work, the RTX 4000 SFF is the only option. It has 48 RT cores, 192 tensor cores, 4 display outputs, and support for DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4. Its 99.84 GPixel/s pixel rate and 299.5 GTexel/s texture rate make it suitable for rendering tasks. The 70 W TDP and 250 W suggested PSU allow installation in power-constrained systems. Its benchmark results are recorded, and its 95th percentile ranking shows it performs well relative to the database population.

The choice depends on the workload. If the task requires floating-point compute at scale, the MI455X is the specified part. If the task requires graphics output, ray tracing, or tensor operations, the RTX 4000 SFF is the specified part. There is no overlap in capability, and the data does not support using either card for the other's domain.

FAQ

Q: What is the FP32 performance difference between the two GPUs?

A: The AMD Instinct MI455X delivers 157.3 TFLOPS FP32, while the NVIDIA RTX 4000 SFF Ada Generation delivers 19.17 TFLOPS FP32. The MI455X provides approximately 8.2 times the FP32 throughput.

Q: How much memory does each card have, and what type?

A: The MI455X has 432 GB of HBM4 memory with a 24,576-bit bus and 23.3 TB/s bandwidth. The RTX 4000 SFF has 20 GB of GDDR6 memory with a 160-bit bus and 280.0 GB/s bandwidth.

Q: Does the AMD card support display outputs?

A: No. The MI455X has no display outputs. The NVIDIA RTX 4000 SFF has 4x mini-DisplayPort 1.4a outputs.

Q: What are the power requirements for each card?

A: The MI455X has a TDP of 2300 W and a suggested PSU of 2700 W. The RTX 4000 SFF has a TDP of 70 W and a suggested PSU of 250 W.

Q: Which card has ray tracing and tensor core support?

A: The NVIDIA RTX 4000 SFF Ada Generation has 48 RT cores and 192 tensor cores. The AMD Instinct MI455X lists no RT cores and no tensor cores.

Q: What are the benchmark results for the RTX 4000 SFF?

A: The RTX 4000 SFF scores 124,812 on Geekbench OpenCL and 109,364 on Geekbench Vulkan, with an average benchmark score of 117,088. The MI455X has no recorded benchmark scores.

Specification Differences

| Specification | AMD Instinct MI455X | NVIDIA RTX 4000 SFF Ada Generation |

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

| Architecture | CDNA 5.0 | Ada Lovelace |

| Process Node | 2 nm | 5 nm |

| Transistors | 320,000 million | 35,800 million |

| Die Size | 2,990 mm² | 294 mm² |

| Transistor Density | 107.0M / mm² | 121.8M / mm² |

| Base Clock | 1000 MHz | 720 MHz |

| Boost Clock | 2400 MHz | 1560 MHz |

| Memory Size | 432 GB | 20 GB |

| Memory Type | HBM4 | GDDR6 |

| Memory Bus Width | 24,576 bit | 160 bit |

| Memory Bandwidth | 23.3 TB/s | 280.0 GB/s |

| Shading Units | 32,768 | 6,144 |

| TMUs | 1,024 | 192 |

| ROPs | 0 | 64 |

| RT Cores | None | 48 |

| Tensor Cores | None | 192 |

| Pixel Rate | 0 MPixel/s | 99.84 GPixel/s |

| Texture Rate | 2,457.6 GTexel/s | 299.5 GTexel/s |

| FP32 | 157.3 TFLOPS | 19.17 TFLOPS |

| FP16 | 157.3 TFLOPS (1:1) | 19.17 TFLOPS (1:1) |

| TDP | 2300 W | 70 W |

| Suggested PSU | 2700 W | 250 W |

| Slot Width | EAM Module | Dual-slot |

| Bus Interface | PCIe 6.0 x16 | PCIe 4.0 x16 |

| Display Outputs | No outputs | 4x mini-DisplayPort 1.4a |

| DirectX | N/A | 12 Ultimate (12_2) |

| OpenGL | N/A | 4.6 |

| Vulkan | N/A | 1.4 |

| Dimensions | Not listed | 168 mm (6.6 inches) length, 69 mm (2.7 inches) height |

| Release Date | 2026-07-22 | 2023-03-20 |

| Production Status | Not listed | Active |

| Predecessor | Radeon Instinct | Workstation Ampere |

| Successor | Not listed | Blackwell PRO W |