GPU Comparison

Head-to-Head Benchmarks

The benchmark data paints a split picture, with each GPU claiming a decisive victory in a different workload. In the Geekbench OpenCL test, the NVIDIA GeForce GTX 950M posts a score of 9,745, while the AMD Radeon 550X scores 8,866. That translates to a 9% advantage for NVIDIA, a meaningful margin that suggests the GTX 950M has a clear edge in general-purpose compute tasks as measured by OpenCL. The magnitude of this win is not trivial; it positions the GTX 950M closer to the performance tier of desktop-class parts from its era, as evidenced by its nearest rival list including the NVIDIA GeForce GTX 980 at an average score of 8,167 (a -0.4% delta).

However, the tables turn dramatically in the Geekbench Vulkan test. Here, the AMD Radeon 550X scores 8,970, against a mere 6,525 for the GTX 950M. This is a 37.5% lead for AMD, a massive swing that dwarfs the NVIDIA advantage in OpenCL. The implication is clear: under the Vulkan API, the Radeon 550X is in a different league entirely, outperforming its rival by more than a third. This is not a marginal win; it is a rout. The data suggests that the AMD architecture is far more efficient at leveraging Vulkan's low-level hardware access, while NVIDIA's Maxwell design appears to struggle under the same API.

Looking at the broader average benchmark scores, the AMD Radeon 550X achieves 8,918, while the GTX 950M averages 8,135. This means that across the two tests, the AMD part holds an overall lead of roughly 9.6% in average score. The Radeon 550X's percentile ranking among all GPUs is 45, versus 42 for the GTX 950M. While both sit in the lower-middle range of the performance spectrum, the AMD part's slightly higher percentile reflects its stronger aggregate showing, driven almost entirely by its Vulkan dominance.

The nature of the wins is asymmetric. The GTX 950M's victory is a moderate, workmanlike lead in OpenCL. The Radeon 550X's victory is a spectacular, API-specific blowout in Vulkan. For users whose workloads are Vulkan-centric, the choice is obvious. For those relying on OpenCL, the GTX 950M is the safer bet. The data leaves no room for a single "overall winner" without weighting the importance of each API, and that weighting will vary by use case.

Architecture Differences

The two GPUs are built on fundamentally different architectural philosophies and process technologies. The AMD Radeon 550X is built on the GCN 4.0 architecture, using the Lexa chip, and fabricated on a 14 nm process at GlobalFoundries. The NVIDIA GeForce GTX 950M, by contrast, uses the Maxwell architecture with the GM107 chip, manufactured on a much older 28 nm process at TSMC. This process gap is significant: the smaller 14 nm node allows AMD to pack 2,200 million transistors into a die size of just 103 mm², yielding a transistor density of 21.4M per mm². NVIDIA's 28 nm process is far less dense, fitting 1,870 million transistors into a larger 148 mm² die, for a density of just 12.6M per mm².

The core configurations differ substantially. The Radeon 550X field 512 shading units, 32 texture mapping units, and 16 ROPs. The GTX 950M has more of everything: 640 shading units, 40 TMUs, and 16 ROPs. This gives NVIDIA a theoretical raw throughput advantage in texture fill rate (44.96 GTexel/s versus 38.98 GTexel/s) and FP32 compute (1,438.7 GFLOPS versus 1,247.2 GFLOPS). However, the Radeon 550X counters with a higher pixel rate (19.49 GPixel/s versus 17.98 GPixel/s). Clock speeds are also in AMD's favor: the Radeon 550X has a base clock of 1082 MHz and a boost of 1218 MHz, while the GTX 950M runs at 993 MHz base and 1124 MHz boost.

Memory is where the two diverge most starkly. The Radeon 550X comes with 2 GB of GDDR5 memory on a 128-bit bus, delivering 112.0 GB/s of bandwidth. The GTX 950M offers 4 GB of DDR3 memory, also on a 128-bit bus, but its bandwidth is a paltry 28.80 GB/s, nearly four times lower. This is a crippling disadvantage for NVIDIA in memory-intensive workloads, and likely a key factor in the Vulkan performance gap. API support also differs: AMD lists DirectX 12 (12_0), OpenGL 4.6, and Vulkan 1.3, while NVIDIA lists DirectX 12 (11_0), OpenGL 4.6, and Vulkan 1.4. The higher Vulkan version on NVIDIA does not translate to better performance in the benchmark data.

Power consumption and physical design tell another story. The Radeon 550X is rated at 50 W TDP, is a dual-slot card, and requires no power connectors, with a suggested PSU of 250 W. The GTX 950M has a 75 W TDP, is classified as an IGP (integrated graphics processor), and its display outputs are "Portable Device Dependent", reflecting its laptop-oriented design. The Radeon 550X is a 145 mm (5.7 inches) discrete card with standard display outputs (1x DVI, 1x HDMI 2.0b, 1x DisplayPort 1.4a), while the GTX 950M has no listed dimensions.

FAQ

Q: Which GPU wins in OpenCL performance?

A: The NVIDIA GeForce GTX 950M wins decisively, scoring 9,745 versus 8,866 for the AMD Radeon 550X, a 9% lead.

Q: Which GPU wins in Vulkan performance?

A: The AMD Radeon 550X wins by a massive 37.5%, scoring 8,970 against the GTX 950M's 6,525.

Q: How do the average benchmark scores compare?

A: The AMD Radeon 550X has an average benchmark score of 8,918, while the GTX 950M averages 8,135. The Radeon 550X also ranks higher in percentile, at 45 versus 42 for the GTX 950M.

Q: What is the memory bandwidth difference?

A: The AMD Radeon 550X offers 112.0 GB/s of bandwidth with 2 GB of GDDR5 memory, while the GTX 950M has 28.80 GB/s with 4 GB of DDR3 memory. AMD's bandwidth is nearly four times higher.

Q: Which GPU has more shading units?

A: The NVIDIA GeForce GTX 950M has 640 shading units, compared to 512 on the AMD Radeon 550X. However, despite fewer units, the AMD part wins in Vulkan.

Q: What is the process node difference?

A: The AMD Radeon 550X is built on a 14 nm process at GlobalFoundries, while the NVIDIA GTX 950M uses a 28 nm process at TSMC. The smaller node gives AMD a much higher transistor density (21.4M per mm² versus 12.6M per mm²).

Specification Differences

| Specification | AMD Radeon 550X | NVIDIA GeForce GTX 950M |

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

| Architecture | GCN 4.0 | Maxwell |

| Process Node | 14 nm | 28 nm |

| Foundry | GlobalFoundries | TSMC |

| Transistors | 2,200 million | 1,870 million |

| Die Size | 103 mm² | 148 mm² |

| Transistor Density | 21.4M / mm² | 12.6M / mm² |

| Base Clock | 1082 MHz | 993 MHz |

| Boost Clock | 1218 MHz | 1124 MHz |

| Memory Size | 2 GB | 4 GB |

| Memory Type | GDDR5 | DDR3 |

| Memory Clock | 1750 MHz (7 Gbps effective) | 900 MHz (1800 Mbps effective) |

| Memory Bandwidth | 112.0 GB/s | 28.80 GB/s |

| Shading Units | 512 | 640 |

| TMUs | 32 | 40 |

| Pixel Rate | 19.49 GPixel/s | 17.98 GPixel/s |

| Texture Rate | 38.98 GTexel/s | 44.96 GTexel/s |

| FP32 Performance | 1,247.2 GFLOPS | 1,438.7 GFLOPS |

| TDP | 50 W | 75 W |

| Slot Width | Dual-slot | IGP |

| Suggested PSU | 250 W | Not specified |

| Display Outputs | 1x DVI, 1x HDMI 2.0b, 1x DisplayPort 1.4a | Portable Device Dependent |

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

| Vulkan Support | 1.3 | 1.4 |

| Release Date | 2019-03-26 | 2015-03-12 |

| Predecessor | Polaris | GeForce 800M |

| Successor | Vega | GeForce 10 Mobile |

The Verdict

The data does not support a single universal recommendation. Instead, it points to a clear split based on workload and API priority. For users who rely heavily on OpenCL compute, the NVIDIA GeForce GTX 950M is the superior choice, with a 9% lead in that specific benchmark. Its higher shading unit count (640 versus 512), higher texture rate (44.96 GTexel/s versus 38.98 GTexel/s), and higher FP32 throughput (1,438.7 GFLOPS versus 1,247.2 GFLOPS) all align with this result, suggesting that raw shader throughput matters more than memory bandwidth in OpenCL workloads.

For users who prioritize Vulkan performance, the AMD Radeon 550X is the only rational pick. Its 37.5% lead in the Vulkan benchmark is overwhelming and cannot be ignored. The data suggests that AMD's GCN 4.0 architecture, with its 112.0 GB/s of memory bandwidth, is far better optimized for Vulkan's explicit, low-overhead model. The GTX 950M's DDR3 memory and older Maxwell architecture appear to bottleneck its Vulkan performance severely.

The overall average benchmark score favors AMD (8,918 versus 8,135), as does the percentile ranking (45 versus 42). In a straight average, the Radeon 550X is the better-rounded GPU. However, the disparity between the two API results is so large that an average score obscures more than it reveals. A user who only runs OpenCL would see the GTX 950M as clearly superior; a user who only runs Vulkan would see the Radeon 550X as vastly superior. The truth is that both are correct, depending on context.

Where Each One Wins

NVIDIA GeForce GTX 950M wins in:

• OpenCL compute workloads, with a 9% score advantage (9,745 versus 8,866).
• Raw shading power, with 640 shading units versus 512, and higher FP32 performance (1,438.7 GFLOPS versus 1,247.2 GFLOPS).
• Texture throughput, achieving 44.96 GTexel/s compared to 38.98 GTexel/s.
• Memory capacity, offering 4 GB versus 2 GB, which could be advantageous in specific multi-tasking or larger dataset scenarios despite the lower bandwidth.
• Scenarios where a lower Vulkan API version (1.3 on AMD) might be a compatibility concern, though the GTX 950M's higher Vulkan 1.4 support did not help its benchmark score.

AMD Radeon 550X wins in:

• Vulkan performance, with a massive 37.5% lead (8,970 versus 6,525).
• Memory bandwidth, delivering 112.0 GB/s versus 28.80 GB/s, a nearly 4x advantage that is likely the root cause of its Vulkan dominance.
• Pixel fill rate, at 19.49 GPixel/s versus 17.98 GPixel/s, indicating faster rasterization throughput.
• Power efficiency, with a 50 W TDP versus 75 W, and a lower suggested PSU requirement (250 W versus unspecified for NVIDIA).
• Physical design flexibility, as a dual-slot discrete card with standard display outputs, versus the GTX 950M's IGP form factor with portable-device-dependent outputs.
• Overall average benchmark score (8,918 versus 8,135) and higher percentile ranking (45 versus 42).