AMD Instinct MI350X vs NVIDIA RTX A400 Comparison

Head-to-Head Benchmarks

The AMD Instinct MI350X and NVIDIA RTX A400 occupy entirely different segments of the GPU spectrum, and the recorded data reflects this divide. The MI350X, built on CDNA 4.0 architecture, delivers compute performance that places it in a different performance class. Its FP32 throughput is rated at 72.09 TFLOPS, which is approximately 26.6 times the RTX A400's 2.706 TFLOPS. The FP16 figures mirror this exactly, with both cards offering 1:1 FP16 to FP32 ratios, meaning the MI350X also delivers 72.09 TFLOPS FP16 against the A400's 2.706 TFLOPS.

Texture throughput tells a similarly lopsided story. The MI350X achieves 2,252.8 GTexel/s, while the RTX A400 manages 42.29 GTexel/s. This represents a performance gap of roughly 53 times, driven by the MI350X's 1024 texture mapping units compared to the A400's 24 TMUs. Pixel rate, however, is where the A400 registers its only absolute advantage: the RTX A400 produces 28.19 GPixel/s, while the MI350X is recorded at 0 MPixel/s, as it has no raster output units and no display outputs.

Memory bandwidth further emphasizes the divide. The MI350X uses 288 GB of HBM3e across an 8192-bit bus, yielding 8.19 TB/s of bandwidth. The RTX A400 has 4 GB of GDDR6 on a 64-bit bus, producing 96.00 GB/s. The MI350X's bandwidth advantage is roughly 85 times, which is consistent with its data-center compute positioning.

The RTX A400 does have recorded benchmark scores. Its Geekbench OpenCL score is 22844, and its Vulkan score is 22237. Passmark results include 5983 for G3D, 2557 for GPU compute, 899 for G2D, and lower scores for DirectX tests: 87 for DirectX 9, 37 for DirectX 11, 32 for DirectX 10, and 27 for DirectX 12. The MI350X has no recorded benchmark scores in the database, which is consistent with its OAM module form factor and lack of display outputs; it is not designed for the conventional graphics workloads these tests represent.

The average benchmark score for the RTX A400 is 6078, placing it at the 35th percentile among all GPUs. Its nearest rivals in the database are closely clustered: the NVIDIA GeForce MX230 scores 6077 (0% delta), the Quadro P2000 scores 6049 (0.5% faster), the Intel Iris Pro Graphics 6200 scores 6117 (-0.6% slower), and the AMD Radeon 760M scores 6019 (1% faster). These deltas show the A400 sits in a tight performance band with other entry-level and older workstation parts, with no rival exceeding a 1% difference.

Where Each One Wins

The data indicates that the AMD Instinct MI350X wins decisively in raw compute throughput, memory capacity, and memory bandwidth. Its FP32 and FP16 figures of 72.09 TFLOPS are the primary metrics for AI training and inference workloads, where large matrix operations dominate. The 288 GB HBM3e memory capacity is substantial, and the 8.19 TB/s bandwidth supports data-intensive operations without memory-bound stalls. The 8192-bit bus width is the widest recorded in the database, and the 8.19 TB/s bandwidth is a direct consequence. The 185,000 million transistors on a 2380 mm² die, manufactured on a 3 nm process at TSMC, indicate a design optimized for maximum compute density.

The NVIDIA RTX A400 wins in areas relevant to desktop workstation graphics. It has display outputs (4x mini-DisplayPort 1.4a), which the MI350X completely lacks. It also has a pixel rate of 28.19 GPixel/s, whereas the MI350X records 0 MPixel/s. The A400 supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4, while the MI350X lists N/A for all three APIs. This makes the A400 usable for graphics rendering, CAD, and similar tasks that require rasterization and display output. Its 50 W TDP and single-slot form factor allow installation in conventional desktop systems, while the MI350X requires a 1400 W suggested PSU and occupies an OAM module slot.

The A400's 6 RT cores and 24 tensor cores are recorded, while the MI350X lists null for both. This suggests the A400 has dedicated hardware for ray tracing and tensor operations, though its overall compute throughput is far lower. The MI350X's 16384 shading units dwarf the A400's 768, indicating that the MI350X relies on massive parallel shading units rather than specialized RT or tensor cores.

Architecture Differences

The two GPUs are built on fundamentally different architectures. The AMD Instinct MI350X uses CDNA 4.0, while the NVIDIA RTX A400 uses Ampere. The MI350X is manufactured on a 3 nm process at TSMC, while the A400 uses an 8 nm process at Samsung. This process difference contributes to the transistor density gap: the MI350X packs 185,000 million transistors into a 2380 mm² die, yielding a density of 77.7M transistors per mm². The A400 has 8,700 million transistors on a 200 mm² die, for a density of 43.5M per mm².

The compute configurations differ sharply. The MI350X has 16384 shading units, 1024 TMUs, and no ROPs. The A400 has 768 shading units, 24 TMUs, and 16 ROPs. The MI350X has no RT cores or tensor cores listed, while the A400 includes 6 RT cores and 24 tensor cores. Clock speeds also differ: the MI350X runs at a 1000 MHz base and 2200 MHz boost, while the A400 runs at 1417 MHz base and 1762 MHz boost. Despite the A400's higher base clock, the MI350X's boost clock is substantially higher, and its massive shading unit count dominates throughput.

Memory architecture is another major divergence. The MI350X uses HBM3e memory clocked at 2000 MHz (8 Gbps effective) across an 8192-bit bus. The A400 uses GDDR6 at 1500 MHz (12 Gbps effective) on a 64-bit bus. The MI350X's 288 GB capacity and 8.19 TB/s bandwidth are orders of magnitude beyond the A400's 4 GB and 96.00 GB/s. The MI350X has no power connectors and is an OAM module, while the A400 is a single-slot card with no power connectors and a 50 W TDP. The suggested PSU for the MI350X is 1400 W, versus 250 W for the A400.

Bus interfaces also differ: the MI350X uses PCIe 5.0 x16, while the A400 uses PCIe 4.0 x8. The MI350X has no display outputs, whereas the A400 has 4x mini-DisplayPort 1.4a. Physical dimensions are recorded for both: the MI350X is 102 mm long and 165 mm wide, while the A400 is 163 mm long and 69 mm high. The MI350X was released on 2025-06-11, while the A400 was released on 2024-04-15. The A400 lists its predecessor as Quadro Turing and successor as Workstation Ada, while the MI350X lists its predecessor as Radeon Instinct.

The Verdict

The recorded data shows two products designed for different purposes, with almost no overlap in target workloads. The AMD Instinct MI350X delivers 72.09 TFLOPS FP32 and FP16, 288 GB of HBM3e memory, and 8.19 TB/s bandwidth. These figures position it for large-scale compute tasks such as AI model training, scientific simulation, and data-center inference. Its lack of display outputs and raster hardware (0 ROPs, 0 MPixel/s pixel rate) confirms it is not intended for graphics output. The 1000 W TDP and OAM form factor require specialized server infrastructure.

The NVIDIA RTX A400 delivers 2.706 TFLOPS FP32 and FP16, 4 GB of GDDR6 memory, and 96.00 GB/s bandwidth. Its 16 ROPs, 28.19 GPixel/s pixel rate, and 4x mini-DisplayPort outputs make it functional for desktop graphics, including CAD, digital content creation, and light compute tasks. Its 50 W TDP and single-slot design allow installation in standard workstations. The A400's benchmark scores, with an average of 6078 and a 35th percentile ranking, place it near the NVIDIA GeForce MX230 (6077), Quadro P2000 (6049), Intel Iris Pro Graphics 6200 (6117), and AMD Radeon 760M (6019), all within a 1% delta.

The data does not support a direct competition between these two accelerators. The MI350X is a compute accelerator with no graphics capability, while the A400 is a graphics workstation card with modest compute. Users requiring display output, rasterization, or API support for DirectX, OpenGL, or Vulkan must select the A400. Users requiring maximum FP32 or FP16 throughput, large memory capacity, or high memory bandwidth must select the MI350X. The MI350X's 26.6 times higher FP32 throughput and 85 times higher memory bandwidth are the defining differentiators.

FAQ

Q: Which GPU has higher FP32 performance?

A: The AMD Instinct MI350X records 72.09 TFLOPS FP32, while the NVIDIA RTX A400 records 2.706 TFLOPS. The MI350X is approximately 26.6 times faster in this metric.

Q: Does the AMD Instinct MI350X support display outputs?

A: No. The MI350X lists "No outputs" for display outputs and has no ROPs, resulting in a 0 MPixel/s pixel rate. The NVIDIA RTX A400 has 4x mini-DisplayPort 1.4a outputs.

Q: What memory configurations do these GPUs use?

A: The MI350X uses 288 GB of HBM3e on an 8192-bit bus with 8.19 TB/s bandwidth. The RTX A400 uses 4 GB of GDDR6 on a 64-bit bus with 96.00 GB/s bandwidth.

Q: How does the RTX A400 compare to its nearest rivals in the database?

A: The A400 has an average benchmark score of 6078, placing it at the 35th percentile. Its nearest rivals are the NVIDIA GeForce MX230 (6077, 0% delta), Quadro P2000 (6049, 0.5% faster), Intel Iris Pro Graphics 6200 (6117, -0.6% slower), and AMD Radeon 760M (6019, 1% faster).

Q: What are the API support differences?

A: The NVIDIA RTX A400 supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. The AMD Instinct MI350X lists N/A for DirectX, OpenGL, and Vulkan, indicating no graphics API support.

Q: What are the power requirements for each?

A: The MI350X has a TDP of 1000 W and a suggested PSU of 1400 W. The RTX A400 has a TDP of 50 W and a suggested PSU of 250 W. Neither card uses external power connectors.