AMD Instinct MI355X vs NVIDIA GeForce RTX 4090 Max-Q Comparison

Head-to-Head Benchmarks

The recorded database contains no direct head-to-head benchmark entries for the AMD Instinct MI355X and the NVIDIA GeForce RTX 4090 Max-Q. Both products register zero benchmark scores and zero wins in the comparative dataset. This absence of measured results means the performance relationship between these two accelerators must be inferred from their architectural specifications and the limited percentile data available.

Both GPUs sit at the 50th percentile against all GPUs in the database, which indicates they occupy comparable positions in the overall distribution, though this percentile is derived from a dataset with no actual benchmark submissions for either product. The average benchmark score for each is recorded as zero, confirming that no validated performance measurements have been logged. Without concrete frame rates, compute throughput tests, or workload-specific results, the data cannot confirm which product delivers higher real-world performance in any given task.

The specification sheets, however, reveal dramatic differences in theoretical compute capability. The AMD Instinct MI355X lists FP32 performance at 78.64 TFLOPS, while the NVIDIA GeForce RTX 4090 Max-Q lists FP32 at 28.31 TFLOPS. This represents a 2.78x advantage for the AMD accelerator in raw single-precision floating-point throughput, assuming both products achieve their listed peak rates under identical conditions. FP16 performance mirrors this gap exactly, with both products listed at a 1:1 ratio to their FP32 figures, meaning the MI355X again delivers 78.64 TFLOPS versus 28.31 TFLOPS for the RTX 4090 Max-Q.

Texture rate tells a similar story. The MI355X lists 2,457.6 GTexel/s, compared to 442.3 GTexel/s for the RTX 4090 Max-Q, a 5.56x difference in texture fill rate. Pixel rate, however, inverts this relationship: the MI355X lists 0 MPixel/s, while the RTX 4090 Max-Q lists 163.0 GPixel/s. This discrepancy stems from the MI355X having zero ROPs, a characteristic of its compute-oriented design, whereas the RTX 4090 Max-Q includes 112 ROPs for rasterization output.

Memory bandwidth further separates the two. The MI355X delivers 8.19 TB/s from 288 GB of HBM3e across an 8192-bit bus. The RTX 4090 Max-Q provides 576.0 GB/s from 16 GB of GDDR6 across a 256-bit bus. The AMD product offers 14.2x the bandwidth and 18x the memory capacity, though these figures reflect fundamentally different market segments.

Architecture Differences

The architectural divide between these two processors is substantial. The AMD Instinct MI355X uses the CDNA 4.0 architecture, built on the MI350 256CU chip, and targets the Instinct (MIx) generation. Its process node is 3 nm, fabricated by TSMC, with 185,000 million transistors on a 2380 mm² die. This yields a transistor density of 77.7M per mm². The NVIDIA GeForce RTX 4090 Max-Q uses the Ada Lovelace architecture, built on the AD103 chip, and belongs to the GeForce 40 Mobile generation. Its process node is 5 nm, also from TSMC, with 45,900 million transistors on a 379 mm² die, giving a density of 121.1M per mm².

The MI355X packs 16,384 shading units, 1,024 TMUs, and zero ROPs. It has no dedicated RT cores and no tensor cores listed. The RTX 4090 Max-Q contains 9,728 shading units, 304 TMUs, 112 ROPs, 76 RT cores, and 304 tensor cores. The AMD chip's lack of ROPs and ray tracing hardware reflects its purpose as a compute accelerator rather than a graphics renderer, while the NVIDIA chip carries the full feature set expected of a mobile GeForce part.

Clock speeds differ notably. The MI355X lists a base clock of 1000 MHz and a boost clock of 2400 MHz. The RTX 4090 Max-Q lists a base clock of 930 MHz and a boost clock of 1455 MHz. The AMD part's higher boost clock, combined with its larger shader count, explains its significant TFLOPS advantage. Memory clocks also diverge: the MI355X runs at 2000 MHz with 8 Gbps effective, while the RTX 4090 Max-Q runs at 2250 MHz with 18 Gbps effective. Despite the NVIDIA product's faster memory clock, the AMD product's 8192-bit bus width overwhelms it in total bandwidth.

Power and interface specifications further separate the two. The MI355X lists a TDP of 1400 W, uses an OAM Module slot width, has no power connectors, and suggests an 1800 W PSU. The RTX 4090 Max-Q lists a TDP of 80 W, uses an IGP slot width, has no power connectors, and lists no suggested PSU. The bus interfaces differ as well: the MI355X uses PCIe 5.0 x16, while the RTX 4090 Max-Q uses PCIe 4.0 x16. The AMD product has no display outputs, while the NVIDIA product's outputs are marked as portable device dependent.

API support highlights the compute-versus-graphics split. The MI355X lists DirectX, OpenGL, and Vulkan as N/A. The RTX 4090 Max-Q lists DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. The NVIDIA product also carries production status marked as active, while the AMD product lists no production status. Release dates place the MI355X at 2025-06-11 and the RTX 4090 Max-Q at 2023-01-02, a gap of roughly two and a half years. The MI355X's predecessor is listed as Radeon Instinct, while the RTX 4090 Max-Q's predecessor is GeForce 30 Mobile and its successor is GeForce 50 Mobile.

Where Each One Wins

Based on the recorded specifications, the AMD Instinct MI355X wins decisively in compute-heavy workloads that rely on raw FP32 or FP16 throughput, massive memory capacity, and extreme memory bandwidth. Its 78.64 TFLOPS in both precisions, 288 GB of HBM3e, and 8.19 TB/s bandwidth position it for large-scale scientific simulation, AI training, and data center inference tasks where data sets exceed what consumer GPUs can hold. The 8192-bit bus width ensures that memory-bound kernels saturate the compute units without stalling on data retrieval.

The NVIDIA GeForce RTX 4090 Max-Q wins in graphics-oriented and ray-traced workloads. Its 76 RT cores and 304 tensor cores enable hardware-accelerated ray tracing and DLSS-style tensor operations, features entirely absent from the MI355X. The 112 ROPs and 163.0 GPixel/s pixel rate allow it to output rendered frames to a display, something the MI355X cannot do with zero display outputs. API compatibility with DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4 makes it usable for gaming and interactive applications, whereas the MI355X lists no graphics API support.

Power efficiency also favors the NVIDIA product. The RTX 4090 Max-Q operates at 80 W TDP, while the MI355X requires 1400 W. This 17.5x difference in power draw means the mobile NVIDIA part can function in laptops and compact devices, while the AMD accelerator demands a server-class OAM module installation with an 1800 W suggested PSU. For workloads that fit within 16 GB of memory and 576.0 GB/s bandwidth, the RTX 4090 Max-Q delivers its 28.31 TFLOPS at a fraction of the power envelope.

The MI355X's 3 nm process node versus the RTX 4090 Max-Q's 5 nm node gives the AMD part a manufacturing advantage in transistor density per area, though the NVIDIA chip's higher density per mm² (121.1M versus 77.7M) shows a more compact design. The MI355X's 2380 mm² die size is 6.3x larger than the RTX 4090 Max-Q's 379 mm², reflecting its server-oriented packaging and HBM3e stacks.

FAQ

Q: Which GPU has higher FP32 compute performance?

A: The AMD Instinct MI355X lists 78.64 TFLOPS FP32, while the NVIDIA GeForce RTX 4090 Max-Q lists 28.31 TFLOPS FP32. The MI355X leads by a factor of 2.78x.

Q: Can the AMD Instinct MI355X do ray tracing?

A: No. The MI355X lists no RT cores and its API support for DirectX, OpenGL, and Vulkan is marked as N/A. The RTX 4090 Max-Q includes 76 RT cores and supports DirectX 12 Ultimate.

Q: How much memory does each GPU have?

A: The MI355X has 288 GB of HBM3e with an 8192-bit bus, while the RTX 4090 Max-Q has 16 GB of GDDR6 with a 256-bit bus. The MI355X provides 18x the capacity and 14.2x the bandwidth.

Q: What is the power consumption difference?

A: The MI355X lists a TDP of 1400 W, while the RTX 4090 Max-Q lists a TDP of 80 W. The MI355X also suggests an 1800 W PSU, while the RTX 4090 Max-Q lists no suggested PSU.

Q: Which GPU supports display outputs?

A: The MI355X has no display outputs, making it unsuitable for graphics rendering to monitors. The RTX 4090 Max-Q lists display outputs as portable device dependent, meaning it can drive displays on compatible laptops.

Q: What process nodes are used?

A: The MI355X uses a 3 nm process from TSMC, while the RTX 4090 Max-Q uses a 5 nm process from the same foundry. The MI355X has 185,000 million transistors, and the RTX 4090 Max-Q has 45,900 million.

The Verdict

The data indicates two products built for different purposes with no overlapping benchmark results to adjudicate a direct winner. The AMD Instinct MI355X is a server-grade compute accelerator with 78.64 TFLOPS FP32, 288 GB of HBM3e, and 8.19 TB/s bandwidth, designed for workloads that demand maximum memory capacity and throughput at 1400 W TDP. It has no graphics outputs, no RT cores, and no gaming API support, making it unsuitable for rendering or interactive applications.

The NVIDIA GeForce RTX 4090 Max-Q is a laptop-oriented graphics processor with 28.31 TFLOPS FP32, 16 GB of GDDR6, and 576.0 GB/s bandwidth, operating at 80 W TDP. It includes 76 RT cores, 304 tensor cores, 112 ROPs, and full DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4 support, enabling ray-traced gaming, content creation, and portable display output.

Users requiring massive memory pools for AI training or scientific computation should select the MI355X, as its 288 GB capacity and 8192-bit bus provide the only viable path for data sets exceeding 16 GB. Users needing a self-contained, power-efficient GPU for graphics or mobile workstations should select the RTX 4090 Max-Q, as its API support and display capabilities are absent from the AMD part. The MI355X's release date of 2025-06-11 places it after the RTX 4090 Max-Q's 2023-01-02 launch, but the architectural focus remains the deciding factor rather than chronology.

Specification Differences

| Specification | AMD Instinct MI355X | NVIDIA GeForce RTX 4090 Max-Q |

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

| Chip | MI350 256CU | AD103 |

| Architecture | CDNA 4.0 | Ada Lovelace |

| Generation | Instinct (MIx) | GeForce 40 Mobile |

| Process Node | 3 nm | 5 nm |

| Transistors | 185,000 million | 45,900 million |

| Die Size | 2380 mm² | 379 mm² |

| Transistor Density | 77.7M / mm² | 121.1M / mm² |

| Base Clock | 1000 MHz | 930 MHz |

| Boost Clock | 2400 MHz | 1455 MHz |

| Memory Clock | 2000 MHz, 8 Gbps effective | 2250 MHz, 18 Gbps effective |

| Memory Size | 288 GB | 16 GB |

| Memory Type | HBM3e | GDDR6 |

| Memory Bus Width | 8192 bit | 256 bit |

| Memory Bandwidth | 8.19 TB/s | 576.0 GB/s |

| Shading Units | 16384 | 9728 |

| TMUs | 1024 | 304 |

| ROPs | 0 | 112 |

| RT Cores | None | 76 |

| Tensor Cores | None | 304 |

| Pixel Rate | 0 MPixel/s | 163.0 GPixel/s |

| Texture Rate | 2,457.6 GTexel/s | 442.3 GTexel/s |

| FP32 Performance | 78.64 TFLOPS | 28.31 TFLOPS |

| FP16 Performance | 78.64 TFLOPS (1:1) | 28.31 TFLOPS (1:1) |

| TDP | 1400 W | 80 W |

| Slot Width | OAM Module | IGP |

| Suggested PSU | 1800 W | None |

| Bus Interface | PCIe 5.0 x16 | PCIe 4.0 x16 |

| Display Outputs | No outputs | Portable Device Dependent |

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

| OpenGL | N/A | 4.6 |

| Vulkan | N/A | 1.4 |

| Production Status | Not listed | Active |

| Release Date | 2025-06-11 | 2023-01-02 |

| Predecessor | Radeon Instinct | GeForce 30 Mobile |

| Successor | None | GeForce 50 Mobile |