AMD Radeon R6 M255DX vs NVIDIA GeForce 940MX Comparison

The AMD Radeon R6 M255DX and the NVIDIA GeForce 940MX are remarkably close competitors in the mobile graphics space, with benchmark data showing a statistical tie. Based on the Geekbench Vulkan test, the AMD Radeon R6 M255DX scores 4867, edging out the NVIDIA GeForce 940MX’s 4749 by a 2.5% margin. This places both GPUs at the 28th percentile of all GPUs, indicating they occupy the same performance tier for legacy and light gaming workloads.

Head-to-Head Benchmarks

The only direct benchmark comparison available is the Geekbench Vulkan test, and the results are extremely tight. The AMD Radeon R6 M255DX achieves a score of 4867, while the NVIDIA GeForce 940MX trails with 4749. This translates to a 2.5% advantage for the AMD part, a margin that is well within the noise of typical benchmark variance. The average benchmark scores reinforce this parity: the Radeon R6 M255DX averages 4867, while the GeForce 940MX averages 4844, a difference of just 0.5%.

Looking at the nearest rivals for each card clarifies the competitive landscape. The Radeon R6 M255DX’s closest competitor is the NVIDIA GeForce GTX 560M, which scores 4855, a negligible 0.2% difference. The GeForce 940MX is also matched against the GTX 560M, with the NVIDIA part trailing by 0.2%. Both cards sit within a narrow band of performance that includes the NVIDIA GeForce GTS 450 (scoring 4893) and even the NVIDIA GeForce RTX 5060 Ti 8 GB (scoring 4901), which is only 0.7% ahead of the AMD part. This data suggests that in Vulkan workloads, these two GPUs are functionally interchangeable in terms of raw performance.

The GeForce 940MX also has a Geekbench OpenCL score of 4939, but no comparable OpenCL result exists for the Radeon R6 M255DX in the data. The head-to-head record shows one win for the AMD Radeon R6 M255DX and zero wins for the NVIDIA GeForce 940MX, but the 2.5% delta is far too small to declare a meaningful victor.

Architecture Differences

The two GPUs come from different architectural generations and design philosophies. The AMD Radeon R6 M255DX is built on the GCN 1.0 architecture using the Jet chip, while the NVIDIA GeForce 940MX uses the Maxwell architecture with the GM107 chip. Both are manufactured on the same 28 nm process node at TSMC, and their transistor densities are nearly identical: the AMD part packs 12.3M transistors per mm², while the NVIDIA part achieves 12.6M per mm².

The physical scale of the chips differs substantially. The AMD Jet chip contains 690 million transistors on a die size of 56 mm², whereas the NVIDIA GM107 chip is much larger, with 1,870 million transistors on a 148 mm² die. This means the NVIDIA chip has roughly 2.7 times the transistor count and a die that is about 2.6 times larger, yet both achieve similar benchmark scores, highlighting the efficiency differences between GCN 1.0 and Maxwell.

Clock speeds are also close but not identical. The AMD part has a base clock of 780 MHz and a boost clock of 855 MHz, while the NVIDIA part runs slightly faster at 795 MHz base and 861 MHz boost. The memory subsystems are fundamentally different: the AMD Radeon R6 M255DX uses System Shared memory, meaning its performance is dependent on the host system’s RAM, while the NVIDIA GeForce 940MX has dedicated 2 GB of GDDR5 memory on a 64-bit bus with 40.10 GB/s of bandwidth. This is a critical distinction, as dedicated memory typically provides more consistent performance than shared system memory.

The compute configurations also differ. The Radeon R6 M255DX has 320 shading units, 20 texture mapping units, and 8 ROPs. The GeForce 940MX has a higher count of 512 shading units and 32 TMUs, but also 8 ROPs. These differences manifest in theoretical throughput figures: the AMD card delivers 547.2 GFLOPS of FP32 performance and a texture rate of 17.10 GTexel/s, while the NVIDIA card offers 881.7 GFLOPS and 27.55 GTexel/s. Despite the NVIDIA part’s clear theoretical advantages, real-world benchmark scores do not reflect a corresponding lead.

FAQ

Q: Which GPU has a higher average benchmark score?

A: The AMD Radeon R6 M255DX has a slightly higher average benchmark score of 4867, compared to the NVIDIA GeForce 940MX’s 4844, a difference of 0.5%.

Q: What is the performance difference in the Geekbench Vulkan test?

A: The AMD Radeon R6 M255DX scores 4867, while the NVIDIA GeForce 940MX scores 4749. The AMD part wins by 2.5%.

Q: Do both GPUs support DirectX 12?

A: Yes, both support DirectX 12, but with different feature levels. The AMD Radeon R6 M255DX supports DirectX 12 (11_1), while the NVIDIA GeForce 940MX supports DirectX 12 (11_0).

Q: How does the memory configuration differ between the two?

A: The AMD Radeon R6 M255DX uses System Shared memory with system-dependent bandwidth, while the NVIDIA GeForce 940MX has 2 GB of dedicated GDDR5 memory on a 64-bit bus with 40.10 GB/s of bandwidth.

Q: Which GPU has more shading units?

A: The NVIDIA GeForce 940MX has 512 shading units, whereas the AMD Radeon R6 M255DX has 320 shading units.

Q: What is the transistor density of each GPU?

A: The AMD Radeon R6 M255DX has a transistor density of 12.3M per mm², while the NVIDIA GeForce 940MX has a density of 12.6M per mm².

Specification Differences

The following table highlights only the fields where the two GPUs differ, based on the available data:

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

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

| Architecture | GCN 1.0 | Maxwell |

| Chip | Jet | GM107 |

| Transistors | 690 million | 1,870 million |

| Die Size | 56 mm² | 148 mm² |

| Base Clock | 780 MHz | 795 MHz |

| Boost Clock | 855 MHz | 861 MHz |

| Memory Clock | System Shared | 1253 MHz / 5 Gbps effective |

| Memory Size | System Shared | 2 GB |

| Memory Type | System Shared | GDDR5 |

| Memory Bus Width | System Shared | 64 bit |

| Memory Bandwidth | System Dependent | 40.10 GB/s |

| Shading Units | 320 | 512 |

| TMUs | 20 | 32 |

| Pixel Rate | 6.840 GPixel/s | 6.888 GPixel/s |

| Texture Rate | 17.10 GTexel/s | 27.55 GTexel/s |

| FP32 Performance | 547.2 GFLOPS | 881.7 GFLOPS |

| TDP | Not specified | 23 W |

| Slot Width | IGP | MXM Module |

| Power Connectors | Not specified | None |

| Bus Interface | IGP | PCIe 3.0 x8 |

| Vulkan Version | 1.2.170 | 1.4 |

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

| Release Date | 2014-01-06 | 2016-06-27 |

| Predecessor | Not specified | GeForce 800M |

| Successor | Not specified | GeForce 10 Mobile |

| Geekbench Vulkan Score | 4867 | 4749 |

The Verdict

The benchmark data tells a clear story: these two GPUs are performance equals in Vulkan workloads. The AMD Radeon R6 M255DX holds a slim 2.5% lead in the head-to-head Vulkan test, and its average score is 0.5% higher than the GeForce 940MX’s. Neither GPU has a decisive edge, and users should not expect a meaningful performance difference between them in real-world applications.

However, the architecture data reveals a different kind of winner. The NVIDIA GeForce 940MX offers far superior theoretical specifications, including 881.7 GFLOPS of FP32 performance versus the AMD part’s 547.2 GFLOPS, and it features dedicated GDDR5 memory instead of shared system memory. This suggests the NVIDIA part may have more headroom in applications that do not rely on Vulkan, such as OpenCL workloads, where it scores 4939. The NVIDIA GPU also has a higher shading unit count and texture rate, indicating it may handle certain compute tasks more efficiently.

For users choosing between these two in a system, the data supports selecting the NVIDIA GeForce 940MX if consistent memory performance and higher theoretical throughput matter. The AMD Radeon R6 M255DX is equally capable in the measured benchmark, but its shared memory architecture makes it dependent on the system’s RAM configuration. Both GPUs are end-of-life products, so the choice will likely come down to which is available in a given laptop rather than a clear performance hierarchy.

Where Each One Wins

AMD Radeon R6 M255DX wins in: The Geekbench Vulkan benchmark, where it scores 4867 versus the GeForce 940MX’s 4749, a 2.5% advantage. It also holds a higher average benchmark score of 4867 compared to 4844. The AMD part supports a higher DirectX 12 feature level (11_1 versus 11_0), which may provide better compatibility with certain DirectX 12 titles. Its smaller die size of 56 mm² and lower transistor count of 690 million could also mean lower manufacturing costs, though this is not reflected in any price data.

NVIDIA GeForce 940MX wins in: Theoretical compute performance, with 881.7 GFLOPS FP32 versus the AMD part’s 547.2 GFLOPS, a 61% advantage. It also has a higher texture rate of 27.55 GTexel/s compared to 17.10 GTexel/s, and double the shading units (512 versus 320). The dedicated 2 GB GDDR5 memory with 40.10 GB/s bandwidth is a significant advantage over the AMD part’s system-shared memory, providing more predictable performance. The NVIDIA GPU also supports Vulkan 1.4, a newer version than the AMD part’s 1.2.170, and has a higher pixel rate of 6.888 GPixel/s versus 6.840 GPixel/s. In OpenCL, the GeForce 940MX scores 4939, a figure the AMD part has no comparable result for.