AMD Instinct MI455X vs NVIDIA GeForce RTX 4090 Max-Q Comparison

Head-to-Head Benchmarks

The recorded database contains no benchmark scores for either the AMD Instinct MI455X or the NVIDIA GeForce RTX 4090 Max-Q. The average benchmark score for both parts is 0, and the head-to-head benchmark array is empty. Consequently, there are no measured wins in either direction to walk through with exact numbers.

The absence of scores means the percentile versus all GPUs is identical for both at 50. This percentile value is not a performance measurement but a placeholder indicating that neither card has an established database entry with recorded results. The data confirms that no FP32, FP16, texture, or pixel rate comparisons can be drawn from measured application tests.

The AMD Instinct MI455X does carry theoretical throughput figures: 157.3 TFLOPS FP32 and 157.3 TFLOPS FP16 (1:1). The NVIDIA GeForce RTX 4090 Max-Q shows 28.31 TFLOPS FP32 and the same 28.31 TFLOPS FP16 (1:1). These are specification-based peak rates, not benchmark outcomes. Without recorded benchmark scores, the database cannot confirm how these theoretical peaks translate into real-world application performance.

Both cards sit at the same percentile rank, which further underscores that no comparative benchmark data exists. The empty wins counters for both items (winsA: 0, winsB: 0) confirm that no test results have been logged. Any statement about which card outperforms the other in specific workloads would be speculation, not database-backed analysis.

Where Each One Wins

Since the benchmark sections are empty, the use-case split must be derived entirely from the physical and architectural specifications recorded in the database.

The AMD Instinct MI455X is built for compute density. Its memory configuration is 432 GB of HBM4 with a 24576-bit bus and 23.3 TB/s bandwidth. That memory capacity and bandwidth are orders of magnitude beyond the NVIDIA part. The NVIDIA GeForce RTX 4090 Max-Q has 16 GB of GDDR6 on a 256-bit bus with 576.0 GB/s bandwidth. For workloads that load large datasets into GPU memory, the AMD card holds 27 times more memory and moves data 40 times faster based on the recorded bandwidth figures. This points to the MI455X being suited for large-scale matrix operations, AI training batches, or scientific simulations where memory footprint exceeds 16 GB.

The NVIDIA card has 76 RT cores and 304 tensor cores. The AMD part has no recorded RT core or tensor core counts. This means the RTX 4090 Max-Q is the only one of the two with hardware specifically designated for ray tracing and tensor operations. The AMD card's architecture is CDNA 5.0, which is compute-oriented, but the database lists no dedicated RT or tensor hardware for it.

The NVIDIA part has a pixel rate of 163.0 GPixel/s and 112 ROPs. The AMD card has 0 ROPs and a 0 MPixel/s pixel rate. This makes the NVIDIA card the only one capable of rasterized graphics output. The AMD card also has no display outputs, while the NVIDIA card's outputs are listed as "Portable Device Dependent," meaning it is intended for laptop displays. For any graphics rendering, gaming, or display-driven workload, the RTX 4090 Max-Q is the only viable option based on the data.

Architecture Differences

The process nodes differ. The AMD Instinct MI455X uses a 2 nm process at TSMC. The NVIDIA GeForce RTX 4090 Max-Q uses a 5 nm process at TSMC. The AMD card packs 320,000 million transistors on a 2990 mm² die, giving a transistor density of 107.0M / mm². The NVIDIA card has 45,900 million transistors on a 379 mm² die, with a density of 121.1M / mm². The NVIDIA chip is denser per square millimeter, but the AMD die is nearly eight times larger in area and holds roughly seven times more transistors.

The AMD architecture is CDNA 5.0, belonging to the Instinct (MIx) generation. The NVIDIA architecture is Ada Lovelace, part of the GeForce 40 Mobile generation. The AMD chip is designated MI450 256CU, indicating 256 compute units. The NVIDIA chip is AD103. The AMD card has 32,768 shading units, 1024 TMUs, and 0 ROPs. The NVIDIA card has 9728 shading units, 304 TMUs, and 112 ROPs.

The AMD card has no RT cores or tensor cores recorded. The NVIDIA card has 76 RT cores and 304 tensor cores. The AMD card's texture rate is 2,457.6 GTexel/s, while the NVIDIA card's texture rate is 442.3 GTexel/s. The AMD card's pixel rate is 0 MPixel/s, while the NVIDIA card's is 163.0 GPixel/s.

Memory architecture differs fundamentally. The AMD card uses HBM4 with a 24576-bit bus, while the NVIDIA card uses GDDR6 with a 256-bit bus. The AMD memory clock is 1900 MHz (7.6 Gbps effective), while the NVIDIA memory clock is 2250 MHz (18 Gbps effective). The effective data rate is higher on the NVIDIA card per pin, but the AMD bus width overwhelms that advantage in total bandwidth.

Specification Differences

The two cards differ across nearly every recorded specification field.

Process and die: AMD is on 2 nm, NVIDIA is on 5 nm. AMD has 320,000 million transistors, NVIDIA has 45,900 million. AMD die size is 2990 mm², NVIDIA is 379 mm². Transistor density: AMD 107.0M / mm², NVIDIA 121.1M / mm².

Clocks: AMD base clock is 1000 MHz, boost is 2400 MHz. NVIDIA base clock is 930 MHz, boost is 1455 MHz. Memory clock: AMD 1900 MHz (7.6 Gbps effective), NVIDIA 2250 MHz (18 Gbps effective).

Memory: AMD has 432 GB of HBM4, NVIDIA has 16 GB of GDDR6. Bus width: AMD 24576 bit, NVIDIA 256 bit. Bandwidth: AMD 23.3 TB/s, NVIDIA 576.0 GB/s.

Compute units: AMD has 32,768 shading units, 1024 TMUs, 0 ROPs. NVIDIA has 9728 shading units, 304 TMUs, 112 ROPs. AMD has no RT cores or tensor cores listed. NVIDIA has 76 RT cores and 304 tensor cores.

Throughput: AMD FP32 is 157.3 TFLOPS, FP16 is 157.3 TFLOPS (1:1). NVIDIA FP32 is 28.31 TFLOPS, FP16 is 28.31 TFLOPS (1:1). AMD texture rate is 2,457.6 GTexel/s, NVIDIA is 442.3 GTexel/s. AMD pixel rate is 0 MPixel/s, NVIDIA is 163.0 GPixel/s.

Power and physical: AMD TDP is 2300 W, NVIDIA TDP is 80 W. AMD suggested PSU is 2700 W, NVIDIA has no suggested PSU listed. AMD slot width is EAM Module, NVIDIA is IGP. Both have no power connectors listed. AMD bus interface is PCIe 6.0 x16, NVIDIA is PCIe 4.0 x16. AMD has no display outputs, NVIDIA outputs are Portable Device Dependent.

API support: AMD has no DirectX, OpenGL, or Vulkan support recorded. NVIDIA has DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4.

Release dates: AMD released 2026-07-22. NVIDIA released 2023-01-02. NVIDIA production status is Active. AMD production status is not recorded.

Predecessors and successors: AMD predecessor is Radeon Instinct, no successor recorded. NVIDIA predecessor is GeForce 30 Mobile, successor is GeForce 50 Mobile.

FAQ

Q: Which card has more memory?

A: The AMD Instinct MI455X has 432 GB of HBM4 memory. The NVIDIA GeForce RTX 4090 Max-Q has 16 GB of GDDR6. The AMD card holds 27 times more memory.

Q: Which card has higher memory bandwidth?

A: The AMD Instinct MI455X has 23.3 TB/s bandwidth. The NVIDIA GeForce RTX 4090 Max-Q has 576.0 GB/s bandwidth. The AMD card provides roughly 40 times more memory bandwidth.

Q: Does either card support ray tracing?

A: The NVIDIA GeForce RTX 4090 Max-Q has 76 RT cores. The AMD Instinct MI455X has no RT core count recorded in the database.

Q: Which card has a higher boost clock?

A: The AMD Instinct MI455X has a boost clock of 2400 MHz. The NVIDIA GeForce RTX 4090 Max-Q has a boost clock of 1455 MHz.

Q: Which card has higher FP32 throughput?

A: The AMD Instinct MI455X has 157.3 TFLOPS FP32. The NVIDIA GeForce RTX 4090 Max-Q has 28.31 TFLOPS FP32. The AMD card's rated FP32 throughput is 5.5 times higher.

Q: Which card has display outputs?

A: The NVIDIA GeForce RTX 4090 Max-Q has display outputs listed as "Portable Device Dependent." The AMD Instinct MI455X has no display outputs.

The Verdict

The data does not support a performance verdict because there are no benchmark results for either card. The database shows zero recorded scores for both, and the head-to-head benchmark array is empty. Any claim of one card being faster than the other cannot be backed by measured data.

What the specifications do show is a clear functional split. The AMD Instinct MI455X is a compute-oriented accelerator with 432 GB of HBM4, 23.3 TB/s bandwidth, 157.3 TFLOPS FP32, and a 2300 W TDP. It has no ROPs, no pixel rate, no display outputs, no graphics API support, and no RT or tensor core counts. It is not a graphics card in the conventional sense. It is a data-center compute module for workloads that need massive memory capacity and raw matrix throughput.

The NVIDIA GeForce RTX 4090 Max-Q is a laptop graphics processor with 16 GB of GDDR6, 76 RT cores, 304 tensor cores, 112 ROPs, a 163.0 GPixel/s pixel rate, and support for DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4. Its 80 W TDP and IGP slot width indicate a mobile, power-limited design. It is the only one of the two that can render graphics, drive a display, or run ray-traced workloads.

The choice between them depends entirely on the intended workload. For large-scale compute tasks that exceed 16 GB of memory footprint, the AMD card is the only option based on memory capacity and bandwidth. For any graphics rendering, display output, or ray tracing workload, the NVIDIA card is the only option based on its recorded feature set. The database contains no crossover where both cards could be measured against the same benchmark, so no direct performance ranking is possible.