GPU Comparison
AMD Radeon RX 6400
RTX A400
PERFORMANCE BENCHMARKS
Analysis: AMD Radeon RX 6400 vs NVIDIA RTX A400
The NVIDIA RTX A400 and AMD Radeon RX 6400 are both low-profile, single-slot graphics cards aimed at compact systems, yet benchmark data reveals they are optimized for very different workloads. The AMD Radeon RX 6400, a RDNA 2 part from the RX 6000 series, wins the majority of head-to-head tests, taking 7 out of 9 comparisons. However, the NVIDIA RTX A400, built on the Ampere architecture, secures decisive victories in specific API and 2D workloads that highlight its distinct strengths. The overall average benchmark scores are nearly identical, 6078 for the A400 versus 6001 for the RX 6400, placing both cards in the 35th percentile of all GPUs, but the distribution of wins tells a more nuanced story about suitability for different tasks.
Where Each One Wins
The data splits cleanly between two usage profiles. The AMD Radeon RX 6400 dominates in raw compute and DirectX rasterization. In the Geekbench OpenCL test, it scores 32011 against the A400’s 22844, a 28.6% advantage that indicates substantially higher general-purpose compute throughput. This lead carries over to DirectX workloads: the RX 6400 beats the A400 by 47.1% in Passmark DirectX 11 (70 vs 37), by 40.7% in DirectX 10 (54 vs 32), and by 10% in DirectX 12 (30 vs 27). Even in legacy DirectX 9, the AMD card leads by 6.5% (93 vs 87). For users running modern games or DirectX-based applications, the RX 6400 is clearly the more capable performer.
The NVIDIA RTX A400, conversely, wins in two specific areas that point to professional or compute-adjacent use. Its Geekbench Vulkan score of 22237 is 35.8% higher than the RX 6400’s 16372, showing a significant edge in Vulkan API workloads. The A400 also wins the Passmark G2D test with a score of 899 versus 722, a 24.5% advantage in 2D graphics performance, which is relevant for desktop environments, CAD-like 2D rendering, or multi-monitor setups with high-resolution UI elements. The A400’s wins are fewer but targeted, suggesting it is tuned for specific API environments rather than broad rasterization throughput.
Architecture Differences
The two cards are built on fundamentally different architectures and manufacturing processes. The NVIDIA RTX A400 uses the GA107 chip on the Ampere architecture, fabricated by Samsung on an 8 nm process. The AMD Radeon RX 6400 uses the Navi 24 chip on the RDNA 2.0 architecture, fabricated by TSMC on a 6 nm process. The process node difference is notable: AMD’s 6 nm process yields a smaller die (107 mm²) and higher transistor density (50.5M per mm²) compared to NVIDIA’s 8 nm process with a 200 mm² die and 43.5M per mm² density. Despite the smaller die, the RX 6400 packs fewer total transistors (5,400 million vs 8,700 million), but its architecture extracts more performance per transistor in rasterization.
Core configuration differs significantly. Both have 768 shading units, but the RX 6400 has double the texture mapping units (48 vs 24) and double the render output units (32 vs 16). This explains the RX 6400’s higher pixel rate (74.27 GPixel/s vs 28.19 GPixel/s) and texture rate (111.4 GTexel/s vs 42.29 GTexel/s). The RX 6400 also has 12 ray tracing cores versus the A400’s 6 RT cores. The A400 counters with 24 tensor cores, which the RX 6400 lacks entirely, indicating NVIDIA’s focus on AI-accelerated workloads. Memory clocks differ, with the RX 6400 running at 16 Gbps effective versus the A400’s 12 Gbps, giving the AMD card 128.0 GB/s bandwidth versus 96.00 GB/s, despite both using a 64-bit bus and 4 GB GDDR6.
The FP32 compute figures reflect the architectural split: the RX 6400 delivers 3.565 TFLOPS versus the A400’s 2.706 TFLOPS, a 31.8% advantage. In FP16, the RX 6400 doubles its FP32 rate to 7.130 TFLOPS due to a 2:1 ratio, while the A400 offers only 1:1 FP16 performance at 2.706 TFLOPS. This makes the RX 6400 substantially faster for half-precision compute tasks, while the A400’s tensor cores provide a different path for AI inference that the RX 6400 cannot match.
The Verdict
Based strictly on the benchmark results, the AMD Radeon RX 6400 is the better choice for most general-purpose graphics and compute workloads. It wins the crucial G3D test (7673 vs 5983, a 22% lead), which is a strong proxy for overall 3D rendering performance, and it leads in every DirectX version tested. For gaming, DirectX-based applications, or OpenCL compute, the RX 6400’s higher pixel rate, texture rate, and FP32 throughput translate directly into measurable performance advantages. The card’s 53 W TDP is only 3 W higher than the A400’s 50 W, so the efficiency cost is negligible for the performance gain.
The NVIDIA RTX A400 is the better choice only for specific use cases where its Vulkan performance and 2D capabilities matter more than DirectX or OpenCL throughput. The 35.8% Vulkan lead suggests that applications leveraging Vulkan for compute or rendering will run faster on the A400. The 24.5% G2D advantage makes it suitable for professional desktop environments or 2D design work where UI responsiveness is critical. Additionally, the presence of tensor cores gives the A400 capabilities that the RX 6400 lacks entirely, which is relevant for AI inference workloads even if the benchmark scores do not capture this directly.
The overall average scores are nearly tied, 6078 for the A400 versus 6001 for the RX 6400, but this masks the RX 6400’s dominance in the most common workloads. Users should select the RX 6400 for gaming or general 3D work, and the A400 only if they specifically need Vulkan performance, superior 2D rendering, or tensor core acceleration.
FAQ
Q: Which card has a higher average benchmark score?
A: The NVIDIA RTX A400 has an average benchmark score of 6078, while the AMD Radeon RX 6400 scores 6001, a difference of less than 1.3%.
Q: How much faster is the AMD Radeon RX 6400 in the Passmark G3D test?
A: The RX 6400 scores 7673 versus the A400’s 5983, giving AMD a 22% lead in this 3D graphics benchmark.
Q: Where does the NVIDIA RTX A400 have its biggest advantage?
A: The A400’s largest win is in the Geekbench Vulkan test, where it scores 22237 versus the RX 6400’s 16372, a 35.8% advantage.
Q: Do both cards have the same amount of memory?
A: Yes, both the NVIDIA RTX A400 and AMD Radeon RX 6400 have 4 GB of GDDR6 memory on a 64-bit bus.
Q: Which card has higher memory bandwidth?
A: The AMD Radeon RX 6400 has 128.0 GB/s bandwidth, while the NVIDIA RTX A400 has 96.00 GB/s, a difference driven by the RX 6400’s 16 Gbps effective memory clock versus the A400’s 12 Gbps.
Q: What is the release date of each card?
A: The AMD Radeon RX 6400 was released on 2024-04-15, and the NVIDIA RTX A400 was released on 2022-01-18.
Head-to-Head Benchmarks
The most decisive win for the AMD Radeon RX 6400 comes in the Geekbench OpenCL test, where it scores 32011 against the A400’s 22844, a 28.6% margin. This test measures general compute performance across a wide range of workloads, and the RX 6400’s higher FP32 throughput (3.565 TFLOPS vs 2.706 TFLOPS) and doubled texture units are the likely drivers. The RX 6400 also wins the Passmark DirectX 11 test by a massive 47.1% (70 vs 37), which is its largest percentage victory. This indicates a substantial advantage in legacy DirectX 11 games and applications, where the RX 6400’s higher pixel rate of 74.27 GPixel/s versus 28.19 GPixel/s provides a clear edge.
The DirectX 12 test shows a narrower gap: the RX 6400 wins 30 to 27, a 10% margin. This suggests that while the AMD card remains ahead in modern APIs, the A400’s Ampere architecture closes some of the gap in more efficient rendering paths. The DirectX 9 test is even closer, with the RX 6400 winning 93 to 87, a 6.5% margin. The RX 6400 also wins the Passmark G3D test (7673 vs 5983, 22% lead) and the GPU compute test (2812 vs 2557, 9.1% lead), reinforcing its overall compute superiority.
The NVIDIA RTX A400’s biggest win is in the Geekbench Vulkan test, where it scores 22237 versus 16372, a 35.8% advantage. This is a striking reversal from the OpenCL result, indicating that the A400’s driver and hardware implementation are significantly better optimized for Vulkan’s low-level API. The A400 also wins the Passmark G2D test with 899 versus 722, a 24.5% lead, which measures 2D graphics operations like window rendering and image blitting. This suggests the A400 provides a smoother desktop experience in multi-monitor or high-resolution 2D environments.
Specification Differences
The two cards differ across nearly every specification field. The manufacturing process is a key differentiator: the AMD Radeon RX 6400 uses a 6 nm TSMC process, while the NVIDIA RTX A400 uses an 8 nm Samsung process. This leads to different die sizes (107 mm² for AMD vs 200 mm² for NVIDIA) and transistor counts (5,400 million vs 8,700 million). The RX 6400 has a higher transistor density of 50.5M per mm² versus 43.5M per mm² for the A400.
Clock speeds vary substantially. The RX 6400 has a base clock of 1923 MHz and a boost clock of 2321 MHz, with a game clock of 2039 MHz. The A400 has a base clock of 1417 MHz and a boost clock of 1762 MHz. The memory clock also differs, with the RX 6400 running at 16 Gbps effective versus the A400’s 12 Gbps. Both cards have 4 GB GDDR6 memory on a 64-bit bus, but the RX 6400 achieves 128.0 GB/s bandwidth versus 96.00 GB/s for the A400.
Core configurations are notably different despite the same shading unit count (768 each). The RX 6400 has 48 TMUs and 32 ROPs, double the A400’s 24 TMUs and 16 ROPs. The RX 6400 also has 12 ray tracing cores versus 6 on the A400. The A400 is unique in having 24 tensor cores, which the RX 6400 lacks. Pixel rates reflect the ROP differences: 74.27 GPixel/s for AMD versus 28.19 GPixel/s for NVIDIA. Texture rates are similarly lopsided at 111.4 GTexel/s versus 42.29 GTexel/s. FP32 performance favors AMD at 3.565 TFLOPS versus 2.706 TFLOPS, and FP16 performance is even more divergent at 7.130 TFLOPS (2:1) versus 2.706 TFLOPS (1:1).
The power and interface specs are close but not identical. The RX 6400 has a TDP of 53 W versus 50 W for the A400, and both have a suggested PSU of 250 W and no power connectors. Both are single-slot cards. The bus interface differs: the A400 uses PCIe 4.0 x8, while the RX 6400 uses PCIe 4.0 x4. Display outputs also differ, with the A400 offering 4x mini-DisplayPort 1.4a and the RX 6400 offering 1x HDMI 2.1 and 1x DisplayPort 1.4a. The RX 6400 has a launch MSRP of 159 USD.