AMD Radeon R6 M255DX vs NVIDIA GeForce 940M Comparison

The data shows a close contest between two end-of-life mobile graphics solutions, with the AMD Radeon R6 M255DX holding a narrow edge in the only directly comparable benchmark, while the NVIDIA GeForce 940M counters with a decisive advantage in raw compute specifications and a higher overall average score.

Head-to-Head Benchmarks

The single head-to-head benchmark result available is Geekbench Vulkan, where the AMD Radeon R6 M255DX scores 4,867 against the NVIDIA GeForce 940M’s 4,549. This represents a 6.5% lead for the AMD part, a meaningful margin in real-world rendering workloads that leverage the Vulkan API. The AMD GPU’s victory here is notable because it outperforms a larger, more power-hungry discrete solution in a modern cross-platform graphics API.

However, the broader benchmark picture favors NVIDIA. The GeForce 940M’s average benchmark score stands at 5,284, which is 8.6% higher than the Radeon R6 M255DX’s average of 4,867. This discrepancy suggests that in other, non-Vulkan workloads—likely including OpenCL and older DirectX titles—the NVIDIA part pulls ahead. The GeForce 940M’s Geekbench OpenCL score of 6,018 is particularly strong, though no comparable OpenCL result exists for the AMD chip in the data pack.

Looking at the nearest rival positioning, the GeForce 940M sits at the 31st percentile of all GPUs, while the Radeon R6 M255DX sits at the 28th percentile. The NVIDIA part’s nearest rivals include the GeForce GTX 980M (scoring 5,308, just 0.4% higher), the GeForce 930A (5,317, 0.6% higher), and the GeForce 840M (5,322, 0.7% higher). The AMD part’s closest competitors are the GeForce GTX 560M (4,855, 0.2% lower), the GeForce 940MX (4,844, 0.5% lower), and the GeForce GTS 450 (4,893, 0.5% higher). These figures indicate that the GeForce 940M competes in a slightly higher performance tier than the Radeon R6 M255DX, despite the latter’s Vulkan-specific win.

Architecture Differences

The architectural divide between these two GPUs is substantial. The NVIDIA GeForce 940M is built on the Maxwell architecture using the GM107 chip, fabricated on a 28 nm process at TSMC. This chip contains 1,870 million transistors on a 148 mm² die, yielding a transistor density of 12.6 million per square millimeter. The AMD Radeon R6 M255DX uses the older GCN 1.0 architecture with the Jet chip, also on a 28 nm TSMC process, but packing only 690 million transistors on a much smaller 56 mm² die, giving a density of 12.3 million per square millimeter.

The NVIDIA part is a discrete MXM module with a 75 W TDP, while the AMD part is an integrated graphics processor (IGP) with no listed TDP. This fundamental difference in form factor explains much of the performance gap. The GeForce 940M has 512 shading units, 32 texture mapping units, and 16 ROPs, compared to the Radeon R6 M255DX’s 320 shading units, 20 TMUs, and 8 ROPs. The NVIDIA chip’s raw throughput figures are roughly double: pixel rate is 17.57 GPixel/s versus 6.84 GPixel/s, texture rate is 35.14 GTexel/s versus 17.10 GTexel/s, and FP32 compute is 1,124.4 GFLOPS versus 547.2 GFLOPS.

Memory configurations also differ sharply. The GeForce 940M comes with 2 GB of dedicated DDR3 memory on a 64-bit bus, delivering 14.40 GB/s bandwidth. The Radeon R6 M255DX uses system-shared memory with system-dependent bandwidth, which is typically slower and contends with the CPU for access. Clock speeds favor NVIDIA as well: the GeForce 940M runs at 1020 MHz base and 1098 MHz boost, while the AMD part runs at 780 MHz base and 855 MHz boost. API support is comparable, with both supporting DirectX 12 (11_0 for NVIDIA, 11_1 for AMD), OpenGL 4.6, and Vulkan (1.4 for NVIDIA, 1.2.170 for AMD).

FAQ

Q: Which GPU has the higher average benchmark score?

A: The NVIDIA GeForce 940M, with an average score of 5,284 compared to the AMD Radeon R6 M255DX’s 4,867, a difference of approximately 8.6%.

Q: Why does the AMD Radeon R6 M255DX win the Vulkan benchmark despite lower raw specs?

A: The AMD part scores 4,867 in Geekbench Vulkan versus 4,549 for the NVIDIA part, a 6.5% lead. This may be attributed to GCN 1.0’s architecture efficiency in Vulkan workloads, though the exact reason is not specified in the data.

Q: What is the process node for both GPUs?

A: Both the NVIDIA GeForce 940M and AMD Radeon R6 M255DX are fabricated on a 28 nm process at TSMC.

Q: How much memory does each GPU have?

A: The NVIDIA GeForce 940M has 2 GB of dedicated DDR3 memory on a 64-bit bus. The AMD Radeon R6 M255DX uses system-shared memory with no dedicated capacity.

Q: What is the transistor count difference?

A: The NVIDIA GeForce 940M has 1,870 million transistors on a 148 mm² die, while the AMD Radeon R6 M255DX has 690 million transistors on a 56 mm² die. This gives the NVIDIA part roughly 2.7 times more transistors.

Q: Which GPU has better Vulkan API support?

A: The NVIDIA GeForce 940M supports Vulkan 1.4, while the AMD Radeon R6 M255DX supports Vulkan 1.2.170. However, the AMD part scores higher in the Vulkan benchmark.

The Verdict

The data supports a clear but nuanced verdict. For users prioritizing pure compute throughput, texture fill, and pixel fill, the NVIDIA GeForce 940M is the superior choice. Its FP32 performance of 1,124.4 GFLOPS is more than double the Radeon R6 M255DX’s 547.2 GFLOPS, and its texture rate of 35.14 GTexel/s is similarly dominant. The dedicated 2 GB DDR3 memory with 14.40 GB/s bandwidth provides consistent, predictable performance that system-shared memory cannot match.

However, the AMD Radeon R6 M255DX wins the only direct head-to-head test available, the Geekbench Vulkan benchmark, by 6.5%. This suggests that in Vulkan-specific titles or workloads, the AMD part may offer better real-world performance despite its lower theoretical specs. The Radeon’s position as an IGP also means it consumes no discrete power budget, making it suitable for thin-and-light laptops where the 75 W TDP of the GeForce 940M would be prohibitive.

The percentile rankings reinforce this split: the GeForce 940M sits at the 31st percentile of all GPUs, while the Radeon R6 M255DX sits at the 28th. The NVIDIA part’s nearest rivals—the GeForce GTX 980M, 930A, and 840M—are all within 0.7% of its score, indicating it is a mid-pack performer. The AMD part’s rivals, including the GeForce GTX 560M and 940MX, cluster within 0.5%, showing it is similarly competitive within its own tier. Ultimately, the GeForce 940M is the stronger overall product, but the Radeon R6 M255DX is not without merit in specific scenarios.

Specification Differences

| Specification | NVIDIA GeForce 940M | AMD Radeon R6 M255DX |

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

| Architecture | Maxwell | GCN 1.0 |

| Chip | GM107 | Jet |

| Process Node | 28 nm | 28 nm |

| Transistors | 1,870 million | 690 million |

| Die Size | 148 mm² | 56 mm² |

| Base Clock | 1020 MHz | 780 MHz |

| Boost Clock | 1098 MHz | 855 MHz |

| Shading Units | 512 | 320 |

| TMUs | 32 | 20 |

| ROPs | 16 | 8 |

| Pixel Rate | 17.57 GPixel/s | 6.84 GPixel/s |

| Texture Rate | 35.14 GTexel/s | 17.10 GTexel/s |

| FP32 | 1,124.4 GFLOPS | 547.2 GFLOPS |

| Memory Size | 2 GB | System Shared |

| Memory Type | DDR3 | System Shared |

| Memory Bus | 64 bit | System Shared |

| Memory Bandwidth | 14.40 GB/s | System Dependent |

| TDP | 75 W | Not listed |

| Slot Width | MXM Module | IGP |

| Bus Interface | MXM-B (3.0) | IGP |

| Vulkan | 1.4 | 1.2.170 |

| DirectX | 12 (11_0) | 12 (11_1) |

| Release Date | 2015-03-12 | 2014-01-06 |

Where Each One Wins

The NVIDIA GeForce 940M wins in every raw performance metric that matters for traditional gaming and GPU-accelerated compute. Its FP32 throughput of 1,124.4 GFLOPS is 105% higher than the AMD part, making it the clear choice for tasks like video encoding, 3D rendering, and physics simulations that rely on shader compute. The GeForce 940M’s dedicated 2 GB VRAM also provides a decisive advantage in texture-heavy games, where system-shared memory on the Radeon part would cause stuttering and frame drops due to bandwidth contention with the CPU. The NVIDIA part’s higher pixel rate (17.57 GPixel/s versus 6.84 GPixel/s) and texture rate (35.14 GTexel/s versus 17.10 GTexel/s) further cement its dominance in resolution scaling and anisotropic filtering workloads.

The AMD Radeon R6 M255DX wins in the specific case of Vulkan API performance, as demonstrated by its 6.5% lead in the Geekbench Vulkan benchmark. This makes it the better option for users running modern Vulkan-based titles or applications that heavily utilize this API. The Radeon part’s integrated nature also gives it a massive efficiency advantage in system design: with no dedicated memory bus, no MXM module, and no discrete power connector, it can be integrated into compact laptops without the thermal or power overhead of the GeForce 940M. For users who prioritize portability and battery life over peak performance, the Radeon R6 M255DX is the more practical choice. The data also shows that the AMD part’s nearest rivals include the GeForce RTX 5060 Ti 8 GB (scoring 4,901, just 0.7% higher), suggesting that in Vulkan workloads, the Radeon R6 M255DX punches above its weight class relative to much newer hardware.