NVIDIA RTX A400 vs NVIDIA Rubin GPU Comparison

FAQ

Q: What are the average benchmark scores for the NVIDIA RTX A400 and the NVIDIA Rubin GPU?

A: The RTX A400 has an average benchmark score of 6078, while the Rubin GPU has no recorded benchmark scores in the database, giving it an average score of 0.

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

A: The RTX A400 sits within 1% of several rivals. It matches the GeForce MX230 (delta 0%), trails the Intel Iris Pro Graphics 6200 by 0.6%, and leads the Quadro P2000 by 0.5% and the AMD Radeon 760M by 1%.

Q: What are the memory specifications of each card?

A: The RTX A400 uses 4 GB of GDDR6 memory on a 64-bit bus, yielding 96.00 GB/s bandwidth. The Rubin GPU uses 288 GB of HBM4 memory on a 16384-bit bus, yielding 22.1 TB/s bandwidth.

Q: What are the power requirements for these cards?

A: The RTX A400 has a TDP of 50 W and a suggested PSU of 250 W. The Rubin GPU has a TDP of 2300 W and a suggested PSU of 2700 W.

Q: Do both cards support the same APIs?

A: No. The RTX A400 supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. The Rubin GPU lists N/A for DirectX, OpenGL, and Vulkan, indicating it is not designed for standard graphics APIs.

Q: What is the production status and release timing for each?

A: Both are listed as Active in production. The RTX A400 was released on 2024-04-15, while the Rubin GPU is dated 2025-12-31.

The Verdict

The data presents two entirely different products. The NVIDIA RTX A400 is a workstation card aimed at professional graphics and compute tasks within a 50 W envelope. Its benchmark scores, while modest, are real and place it at the 35th percentile of all GPUs. The NVIDIA Rubin GPU is a server-class accelerator with massive compute resources but no recorded benchmark scores, no display outputs, and no standard graphics API support. Its 50th percentile ranking appears to be a placeholder given the zero average score.

For a professional needing a low-profile, single-slot card for CAD or multi-display workstation use, the RTX A400 is the only option with practical graphics benchmarks. For a data center operator focused on large-scale compute, the Rubin GPU offers 28672 shading units, 896 tensor cores, and 288 GB of HBM4 memory, but the database contains no performance validation for it. The choice depends on whether the workload requires traditional graphics APIs and verified scores, which points to the A400, or raw compute scale with unverified metrics, which points to the Rubin.

Head-to-Head Benchmarks

The head-to-head benchmark table in the database is empty, and the Rubin GPU has no individual benchmark entries. Therefore, direct score comparisons are impossible. However, the RTX A400’s recorded data provides context. In Geekbench OpenCL, it scores 22844, and in Geekbench Vulkan, it scores 22237. Passmark tests show 5983 in G3D and 2557 in GPU Compute, with legacy tests like DirectX 10 at 32, DirectX 11 at 37, DirectX 12 at 27, and DirectX 9 at 87.

Without Rubin scores, the only meaningful comparison is architectural capability. The Rubin GPU’s FP32 output is 130.0 TFLOPS versus 2.706 TFLOPS for the A400, a 48x difference. Its texture rate is 2,031.2 GTexel/s versus 42.29 GTexel/s, a 48x difference. Memory bandwidth differs by a factor of 230x, with 22.1 TB/s versus 96.00 GB/s. These are theoretical maxima, not measured performance, and the Rubin GPU lacks any validation in the database.

Specification Differences

The two cards differ across nearly every specification field. The RTX A400 uses the GA107 chip on an 8 nm Samsung process, while the Rubin GPU uses the GR100 chip on a 3 nm TSMC process. Transistor counts are 8,700 million versus 336,000 million, and die sizes are 200 mm² versus 1456 mm². Transistor density is 43.5M per mm² for the A400 and 230.8M per mm² for the Rubin.

Clock speeds show a different design philosophy. The A400 has a base clock of 1417 MHz and boost of 1762 MHz. The Rubin has a lower base of 700 MHz but a higher boost of 2267 MHz. Memory clocks are 1500 MHz (12 Gbps effective) for the A400 and 2695 MHz (10.8 Gbps effective) for the Rubin.

Memory configuration is starkly different. The A400 has 4 GB GDDR6 on a 64-bit bus. The Rubin has 288 GB HBM4 on a 16384-bit bus. Compute units are 768 shading units, 24 TMUs, and 16 ROPs for the A400, versus 28672 shading units, 896 TMUs, and 24 ROPs for the Rubin. The A400 has 6 RT cores and 24 tensor cores; the Rubin has 896 tensor cores but no RT core count listed.

Pixel and texture rates are 28.19 GPixel/s and 42.29 GTexel/s for the A400, versus 54.41 GPixel/s and 2,031.2 GTexel/s for the Rubin. FP32 performance is 2.706 TFLOPS for the A400 and 130.0 TFLOPS for the Rubin. FP16 is 2.706 TFLOPS (1:1) for the A400 and 260.0 TFLOPS (2:1) for the Rubin.

Physical and power characteristics diverge completely. The A400 is single-slot, 163 mm long, 69 mm high, with no power connectors and a 50 W TDP. The Rubin is an SXM module with no dimensions listed, no power connector data, and a 2300 W TDP. The A400 uses PCIe 4.0 x8 and has 4x mini-DisplayPort 1.4a outputs. The Rubin uses PCIe 6.0 x16 and has no display outputs.

Architecture Differences

The RTX A400 is built on the Ampere architecture, part of the Workstation Ampere (Ax000) generation. It uses an 8 nm Samsung process with 8,700 million transistors on a 200 mm² die. The Rubin GPU uses the Rubin architecture, part of the Server Rubin (Rxx) generation, on a 3 nm TSMC process with 336,000 million transistors on a 1456 mm² die. The transistor density difference, 43.5M per mm² versus 230.8M per mm², reflects the node generation gap.

The A400’s memory subsystem is GDDR6 with a 64-bit bus. The Rubin uses HBM4 with a 16384-bit bus, a design choice for bandwidth-intensive server workloads. The A400 includes 6 RT cores and 24 tensor cores for workstation ray tracing and AI acceleration. The Rubin lists 896 tensor cores but no RT core count, suggesting a compute-first design without dedicated ray tracing hardware.

API support confirms the architectural split. The A400 supports DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4, making it usable in standard graphics applications. The Rubin lists N/A for all three APIs, indicating it is not intended for traditional graphics rendering. The Rubin’s FP16 throughput being double its FP32 (260.0 versus 130.0 TFLOPS) versus the A400’s 1:1 ratio shows different precision strategies for AI and HPC workloads.

Where Each One Wins

The RTX A400 wins in any scenario requiring verified, benchmarked performance. Its 22844 Geekbench OpenCL and 22237 Geekbench Vulkan scores are concrete data points. It also wins in workstation integration: it has display outputs, supports standard APIs, and fits a 50 W power envelope with a 250 W suggested PSU. For a professional using CAD, 3D modeling, or multi-display setups, the A400 is the only card with practical, tested graphics capabilities.

The Rubin GPU wins on raw theoretical compute scale. Its 130.0 TFLOPS FP32, 260.0 TFLOPS FP16, 22.1 TB/s memory bandwidth, and 288 GB capacity are orders of magnitude beyond the A400. It also wins on process technology, using a 3 nm node versus 8 nm, and on memory type, using HBM4 versus GDDR6. For a server workload like large-scale AI training or scientific simulation that can use its 28672 shading units and 896 tensor cores, the Rubin is designed for that class of work.

The database shows no measured wins for the Rubin because it has no benchmarks. The A400 has wins in every recorded test by default. The practical verdict is conditional: the A400 wins for verified workstation use, while the Rubin wins for theoretical server compute capacity, pending future benchmark data.