AMD Radeon RX 6400 vs NVIDIA GeForce 940M Comparison

Head-to-Head Benchmarks

The direct comparison between the AMD Radeon RX 6400 and the NVIDIA GeForce 940M is brief but decisive. The database records only two shared benchmark tests, and the AMD part wins both by a massive margin.

In Geekbench OpenCL, the RX 6400 scores 32,011 against the 940M's 6,018. That is a 431.9% advantage, meaning the AMD card delivers more than five times the raw compute throughput in this API. The gap is so wide that the GeForce 940M's score is closer to the RX 6400's Vulkan result (6,018 vs 16,372) than it is to the RX 6400's OpenCL result.

The Geekbench Vulkan test tells a similar story, though the margin narrows in relative terms. The RX 6400 posts 16,372, while the 940M manages 4,549. The delta is 259.9%, so the AMD part is roughly 3.6 times faster in Vulkan. This is notable because Vulkan is a lower-level API that tends to expose hardware efficiency; the fact that the RX 6400 still dominates by this degree points to a fundamental gap in execution resources, not just driver overhead.

The head-to-head record is 2 wins for the RX 6400, 0 for the 940M. There are no shared DirectX or PassMark results in the database, so this comparison rests entirely on these two compute-oriented workloads. Still, the magnitude of the deltas suggests the pattern would hold across gaming and productivity tests if such data existed.

Architecture Differences

The two GPUs come from different design eras and different process technologies. The RX 6400 uses the Navi 24 chip, built on RDNA 2.0 architecture, fabricated by TSMC on a 6 nm process. The 940M uses the GM107 chip, built on NVIDIA's Maxwell architecture, also by TSMC but on a much older 28 nm node. The process gap is substantial: 6 nm versus 28 nm. This alone explains much of the efficiency difference.

Transistor counts reflect the generational divide. The RX 6400 packs 5,400 million transistors into a 107 mm² die, yielding a transistor density of 50.5 million per mm². The 940M has 1,870 million transistors spread across a larger 148 mm² die, for a density of just 12.6 million per mm². The RX 6400 is denser by a factor of four, a direct consequence of the newer node.

Shader resources also favor the RX 6400. The AMD card has 768 shading units, 48 texture mapping units, and 32 render output units. The 940M has 512 shading units, 32 TMUs, and 16 ROPs. In every category, the RX 6400 has more execution hardware, but the ratio is not uniform: the AMD card has 1.5 times the shaders, 1.5 times the TMUs, and 2 times the ROPs. The ROP advantage is particularly relevant for fill-rate-bound workloads.

Clock speeds reinforce the hardware lead. 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 940M runs at 1020 MHz base and 1098 MHz boost. The AMD card's boost clock is more than double the 940M's boost clock. Higher clocks multiplied by more shaders produce the large compute gap seen in the benchmarks.

Memory is another major differentiator. The RX 6400 uses 4 GB of GDDR6 on a 64-bit bus, delivering 128.0 GB/s of bandwidth. The 940M also uses a 64-bit bus but pairs it with 2 GB of DDR3, yielding only 14.40 GB/s. That is a 8.9 times difference in memory bandwidth. For any texture-heavy or frame-buffer-intensive workload, this alone would be decisive.

The RX 6400 also brings ray tracing cores, 12 of them. The 940M has none. The AMD card supports DirectX 12 Ultimate (12_2), while the 940M is limited to DirectX 12 (11_0). Both support OpenGL 4.6 and Vulkan 1.4, so API compatibility is not entirely one-sided. The RX 6400 is a PCIe 4.0 x4 card, while the 940M is an MXM-B (3.0) module, reflecting its laptop-oriented design.

Power figures show the efficiency story. The RX 6400 is rated at 53 W TDP, and the 940M at 75 W TDP. Despite drawing 22 W less, the RX 6400 delivers dramatically higher performance. The RX 6400 is also single-slot with no power connectors, while the 940M is an MXM module with no power connectors. The 940M has no suggested PSU rating, while the RX 6400 suggests a 250 W power supply.

Where Each One Wins

Based on the recorded data, the RX 6400 wins everywhere that can be measured. In OpenCL compute, it is 431.9% ahead. In Vulkan, it is 259.9% ahead. There are no benchmark categories where the 940M comes out on top.

The RX 6400's advantages are structural. It has more shaders, more TMUs, more ROPs, more memory bandwidth, and higher clock speeds. It also has ray tracing hardware and a newer DirectX feature level. The 940M's only potential advantages are its lower peak power draw in absolute terms, though the RX 6400 actually draws less power while performing better, and its MXM form factor, which makes it suitable for certain laptop chassis.

For use cases, the RX 6400 is the clear choice for any modern workload: DirectX 12 Ultimate gaming, ray-traced effects, compute tasks in OpenCL or Vulkan, and any application that benefits from high memory bandwidth. The 940M belongs to an older generation of mobile GPUs, and its 2 GB DDR3 frame buffer at 14.40 GB/s would bottleneck even modest modern titles.

The one scenario where the 940M might seem relevant is legacy laptop compatibility. It is an MXM module, and the RX 6400 is a PCIe card, so they are not physically interchangeable in most systems. But from a pure performance standpoint, the data shows no category where the 940M wins.

The Verdict

The data is unambiguous. The AMD Radeon RX 6400 is the superior GPU by every measured metric. It wins both head-to-head benchmarks, holds a higher average benchmark score, and ranks in a higher percentile among all GPUs.

The RX 6400's average benchmark score is 6,001, placing it in the 35th percentile of all GPUs. The 940M's average score is 5,284, placing it in the 31st percentile. The RX 6400's nearest rivals include the NVIDIA GeForce GTX 770M at 6,000 (0% delta), the NVIDIA RTX PRO 6000 Blackwell Server at 5,996 (0.1% delta), the AMD FirePro W4100 at 5,987 (0.2% delta), and the NVIDIA Quadro K4000M at 5,986 (0.3% delta). The 940M's nearest rivals include the NVIDIA GeForce GTX 980M at 5,308 (0.4% lower), the NVIDIA GeForce 930A at 5,317 (0.6% lower), the NVIDIA GeForce 840M at 5,322 (0.7% lower), and the NVIDIA GeForce GTX 760M at 5,236 (0.9% higher).

Notably, the RX 6400's average score of 6,001 is nearly identical to the 940M's nearest rival, the GTX 980M at 5,308, and the 940M itself scores 5,284. The RX 6400 outperforms the 940M by 717 points in average score, a 13.6% margin.

Who should pick which? A user building a desktop system with a PCIe slot should choose the RX 6400 without hesitation. It offers newer architecture, more memory, higher bandwidth, ray tracing support, and far better benchmark results. A user with a legacy laptop that requires an MXM-B module has no choice but the 940M, but the data shows they would be sacrificing 431.9% in OpenCL performance and 259.9% in Vulkan performance compared to the RX 6400.

The RX 6400 is end-of-life, as is the 940M, but the RX 6400 was released on 2022-01-18, while the 940M dates to 2015-03-12. Seven years of architecture progress separate them, and the benchmark data reflects that gap.

FAQ

Q: Which GPU wins in Geekbench OpenCL?

A: The AMD Radeon RX 6400 wins with a score of 32,011 against the NVIDIA GeForce 940M's 6,018, a 431.9% advantage.

Q: Does the RX 6400 support ray tracing?

A: Yes, the RX 6400 has 12 ray tracing cores. The GeForce 940M has no ray tracing cores.

Q: What is the memory bandwidth difference?

A: The RX 6400 has 128.0 GB/s of bandwidth from 4 GB of GDDR6 on a 64-bit bus. The 940M has 14.40 GB/s from 2 GB of DDR3 on a 64-bit bus.

Q: Which GPU has a higher average benchmark score?

A: The RX 6400 has an average score of 6,001, placing it in the 35th percentile. The 940M has an average score of 5,284, placing it in the 31st percentile.

Q: What DirectX versions do they support?

A: The RX 6400 supports DirectX 12 Ultimate (12_2). The 940M supports DirectX 12 (11_0).

Q: Are these GPUs still in production?

A: No, both are end-of-life. The RX 6400 was released on 2022-01-18, and the 940M was released on 2015-03-12.

Specification Differences

| Specification | AMD Radeon RX 6400 | NVIDIA GeForce 940M |

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

| Architecture | RDNA 2.0 | Maxwell |

| Process Node | 6 nm | 28 nm |

| Transistors | 5,400 million | 1,870 million |

| Die Size | 107 mm² | 148 mm² |

| Transistor Density | 50.5M / mm² | 12.6M / mm² |

| Base Clock | 1923 MHz | 1020 MHz |

| Boost Clock | 2321 MHz | 1098 MHz |

| Memory Size | 4 GB | 2 GB |

| Memory Type | GDDR6 | DDR3 |

| Memory Bandwidth | 128.0 GB/s | 14.40 GB/s |

| Shading Units | 768 | 512 |

| TMUs | 48 | 32 |

| ROPs | 32 | 16 |

| Ray Tracing Cores | 12 | None |

| Pixel Rate | 74.27 GPixel/s | 17.57 GPixel/s |

| Texture Rate | 111.4 GTexel/s | 35.14 GTexel/s |

| FP32 Performance | 3.565 TFLOPS | 1,124.4 GFLOPS |

| TDP | 53 W | 75 W |

| Slot Width | Single-slot | MXM Module |

| Bus Interface | PCIe 4.0 x4 | MXM-B (3.0) |

| Display Outputs | 1x HDMI 2.1, 1x DisplayPort 1.4a | Portable Device Dependent |

| DirectX Support | 12 Ultimate (12_2) | 12 (11_0) |