AMD Radeon Pro 555X vs NVIDIA GeForce GTX 950 Comparison

The AMD Radeon Pro 555X and NVIDIA GeForce GTX 950 are two end-of-life graphics cards from different eras and design philosophies, yet their average benchmark scores place them within 1% of each other. The Radeon Pro 555X, a 14nm mobile part aimed at Apple's Mac lineup, posts an average score of 13,321, while the GTX 950, a 28nm desktop card from NVIDIA's GeForce 900 generation, averages 13,189. This near-identical overall performance, however, masks starkly divergent strengths in individual workloads, making the choice between them entirely dependent on the specific application.

Head-to-Head Benchmarks

The most dramatic disparity in the head-to-head results appears in the Geekbench Metal test, where the AMD Radeon Pro 555X dominates with a score of 14,479 against the GTX 950's 7,172. This represents a massive 101.9% advantage for the AMD card, effectively doubling the NVIDIA card's output. The Metal API is Apple's graphics framework, and the Radeon Pro 555X's architecture is clearly optimized for it, given its intended deployment in Mac systems. In this specific test, the Radeon Pro 555X doesn't just win; it obliterates the competition, a result that underscores the importance of software ecosystem alignment over raw hardware capability.

The tables turn decisively in the Geekbench OpenCL test. Here, the NVIDIA GeForce GTX 950 scores 15,662, surpassing the Radeon Pro 555X's 12,628. The deltaPct of -19.4% in favor of the GTX 950 indicates a solid, but not overwhelming, lead for the NVIDIA card. OpenCL is a cross-platform compute standard, and this result suggests that the Maxwell 2.0 architecture in the GTX 950 handles this particular workload with significantly greater efficiency than the GCN 4.0 architecture in the AMD part.

The pattern continues in the Geekbench Vulkan benchmark, where the GTX 950 extends its lead further. With a score of 16,734, the NVIDIA card is 23.2% ahead of the Radeon Pro 555X's 12,855. Vulkan is a low-overhead graphics and compute API, and the Maxwell 2.0 architecture's strength in this area is evident. Across the three tests, the wins are split 1-2 in favor of the GTX 950, but the magnitude of the AMD win in Metal is far larger than the combined margins of NVIDIA's victories in the other two tests. The average scores, however, nearly converge because the Metal result, despite its extreme delta, is just one of three data points, pulling the AMD average up while the two NVIDIA wins push its own average down to a comparable level.

Where Each One Wins

The data clearly defines the use-case scenarios for each card. The AMD Radeon Pro 555X is the unequivocal winner in any environment that relies on Apple's Metal API. The 101.9% performance advantage in this benchmark means that for macOS-based applications, creative software, and games that leverage Metal, the Radeon Pro 555X is not just competitive but in a different class. This makes it the logical choice for users embedded in the Apple ecosystem, particularly for tasks like video editing, 3D rendering, or GPU-accelerated effects within applications that have deep Metal integration. The 54th percentile ranking across all GPUs, coupled with this specific API dominance, suggests that its real-world value is highly contextual.

The NVIDIA GeForce GTX 950, conversely, is the better performer in OpenCL and Vulkan environments. Its 19.4% lead in OpenCL and 23.2% lead in Vulkan indicate that for cross-platform compute tasks, Linux or Windows gaming, and applications that favor these more universal APIs, the GTX 950 provides a tangible performance advantage. The Vulkan result is particularly relevant for modern game engines, many of which have adopted Vulkan for its efficiency. This makes the GTX 950 a more versatile choice for a general-purpose desktop system where the software stack is not exclusively tied to Apple's frameworks. The GTX 950's 53rd percentile ranking is nearly identical to the AMD card, but its wins are in the more broadly applicable API categories.

Architecture Differences

The two cards are built on fundamentally different architectures from different process nodes. The AMD Radeon Pro 555X is based on the Polaris 21 chip, which utilizes the GCN 4.0 architecture. This chip is manufactured on a 14nm process at GlobalFoundries. In contrast, the NVIDIA GeForce GTX 950 uses the GM206 chip, built on the older Maxwell 2.0 architecture, and is fabricated on a 28nm process at TSMC. This process node difference is significant, as the 14nm node allows AMD to pack 3,000 million transistors into a die size of just 123 mm², yielding a transistor density of 24.4M / mm². The GTX 950, with its 28nm process, has a slightly lower transistor count at 2,940 million, but requires a much larger 228 mm² die, resulting in a transistor density of only 12.9M / mm².

The architectural differences extend to compute capabilities. The AMD card supports FP16 computation at a 1:1 ratio with FP32, offering 1,393.2 GFLOPS for both data types. The NVIDIA card does not list an FP16 capability in the data, focusing its 1.825 TFLOPS entirely on FP32. This makes the Radeon Pro 555X potentially more efficient for workloads that can utilize half-precision arithmetic, a common technique in machine learning and certain graphics effects. The GTX 950's higher FP32 throughput, however, gives it an edge in traditional single-precision compute tasks. Both cards support DirectX 12, but the GTX 950 lists support for the 12_1 feature level, while the Radeon Pro 555X is at 12_0. Both support OpenGL 4.6, but the GTX 950 lists Vulkan 1.4 support compared to the Radeon Pro 555X's Vulkan 1.3.

Specification Differences

The specifications diverge significantly in several key areas beyond performance. The memory configurations are notably different: the AMD Radeon Pro 555X comes equipped with 4 GB of GDDR5 memory, double the 2 GB found on the GTX 950. However, the NVIDIA card has a higher memory clock speed, running at 1653 MHz with 6.6 Gbps effective, compared to the AMD's 1470 MHz and 5.9 Gbps effective. This results in a higher memory bandwidth for the GTX 950 at 105.8 GB/s, despite its smaller capacity, versus the Radeon Pro 555X's 94.08 GB/s. The bus width for both is 128 bit, so the bandwidth difference is purely a function of clock speed.

The compute unit configurations are also divergent. Both cards have 768 shading units and 48 texture mapping units (TMUs), but the ROP count differs. The GTX 950 has 32 ROPs, double the 16 ROPs on the Radeon Pro 555X. This directly contributes to the NVIDIA card's significantly higher pixel rate of 38.02 GPixel/s, compared to the AMD's 14.51 GPixel/s. The texture rate also favors the GTX 950 at 57.02 GTexel/s versus 43.54 GTexel/s. Power and physical specifications differ as well. The Radeon Pro 555X has a TDP of 75 W and is an IGP (integrated graphics processor) with no power connectors, while the GTX 950 has a 90 W TDP, is a dual-slot card requiring a 1x 6-pin power connector, and a suggested PSU of 250 W. The GTX 950 is also a longer card at 202 mm, uses a PCIe 3.0 x16 interface, and has a set of display outputs including DVI, HDMI 2.0, and three DisplayPort 1.2 connections, whereas the Radeon Pro 555X's outputs are listed as "Portable Device Dependent" and uses a PCIe 3.0 x8 interface. The GTX 950 has a launch MSRP of 159 USD.

FAQ

Q: Which card has a higher average benchmark score?

A: The AMD Radeon Pro 555X has a marginally higher average benchmark score of 13,321, compared to the NVIDIA GeForce GTX 950's 13,189.

Q: How large is the performance gap in the Geekbench Metal test?

A: The AMD Radeon Pro 555X is 101.9% ahead of the NVIDIA GeForce GTX 950, scoring 14,479 versus 7,172.

Q: In which API does the NVIDIA GeForce GTX 950 show its largest lead?

A: The GTX 950 shows its largest lead in Geekbench Vulkan, where it scores 16,734, a 23.2% advantage over the Radeon Pro 555X's 12,855.

Q: What is the difference in memory capacity between the two cards?

A: The AMD Radeon Pro 555X has 4 GB of GDDR5 memory, while the NVIDIA GeForce GTX 950 has 2 GB of GDDR5 memory.

Q: How do the process nodes and die sizes compare?

A: The AMD Radeon Pro 555X is built on a 14nm process at GlobalFoundries with a 123 mm² die size, while the NVIDIA GeForce GTX 950 uses a 28nm process at TSMC with a 228 mm² die size.

Q: Which card has a higher pixel fill rate?

A: The NVIDIA GeForce GTX 950 has a much higher pixel rate of 38.02 GPixel/s, compared to the AMD Radeon Pro 555X's 14.51 GPixel/s, due to its 32 ROPs versus 16 on the AMD card.