AMD Radeon RX 550X vs NVIDIA GeForce GTX 675MX Comparison

Head-to-Head Benchmarks

The only direct benchmark comparison recorded in the database is Geekbench OpenCL, and the result is decisive: the NVIDIA GeForce GTX 675MX wins with a score of 10,723 against the AMD Radeon RX 550X's 9,662. That is a 9.9% margin in favor of the NVIDIA part. The data shows a clear, though not overwhelming, performance gap in raw compute workloads.

Looking at the broader average benchmark scores, the pattern shifts. The AMD Radeon RX 550X has an average score of 10,481 across all recorded tests, which places it at the 49th percentile among all GPUs. The NVIDIA GeForce GTX 675MX averages 8,427, sitting at the 43rd percentile. This is a significant inversion: the RX 550X holds a 24.4% higher average score when considering the full suite of benchmarks, but the GTX 675MX wins the one head-to-head test they share.

The database also provides context through nearest rivals. For the RX 550X, its average score of 10,481 puts it 0.8% ahead of the NVIDIA Tesla C2075 (10,400) and 1.2% ahead of the AMD Radeon RX 6500M (10,362). It trails the AMD Radeon R9 M275X by 1% (10,582) and the AMD Radeon RX 6600S by 1.4% (10,629). For the GTX 675MX, the average of 8,427 places it 1.2% ahead of the AMD Radeon R9 M375X (8,325), while it is nearly level with the AMD Radeon 880M (8,436, down 0.1%), the NVIDIA GeForce MX330 (8,458, down 0.4%), and the AMD Radeon HD 8870M (8,462, down 0.4%).

The OpenCL result is the only direct comparison, and it favors the older NVIDIA architecture. However, the average benchmark data tells a different story: the RX 550X is the stronger overall performer when all recorded tests are considered. The GTX 675MX also has a Geekbench Metal score of 6,131, which the AMD part does not have a recorded result for, so that metric cannot be compared directly.

Where Each One Wins

The AMD Radeon RX 550X wins on overall compute consistency. Its average benchmark score of 10,481 is substantially higher than the GTX 675MX's 8,427, a 24.4% advantage. This suggests the RX 550X delivers better performance across a wider range of workloads, not just the single OpenCL test. The 49th percentile ranking versus the 43rd percentile for the GTX 675MX reinforces this: the RX 550X sits closer to the middle of the performance distribution among all GPUs.

The NVIDIA GeForce GTX 675MX wins the specific OpenCL test, scoring 10,723 versus 9,662. That 9.9% margin indicates that in OpenCL compute tasks specifically, the older Kepler architecture is more efficient. The GTX 675MX also has a recorded Metal score of 6,131, which is a platform-specific benchmark (Apple's Metal API) where the RX 550X has no recorded result, so the NVIDIA card has an unopposed presence in that metric.

For use-case guidance, the data points in two directions. If the workload relies on OpenCL, the GTX 675MX is the better choice by a measurable margin. If the workload is more general or uses the average of multiple benchmark types, the RX 550X is the stronger candidate. The AMD card's higher average score and percentile rank suggest it is more versatile, while the NVIDIA card's single-test win indicates specialization in one compute API.

Architecture Differences

The two GPUs come from different manufacturers, nodes, and design philosophies. The AMD Radeon RX 550X uses the Lexa chip built on GCN 4.0 architecture, part of the Polaris (RX 500X) generation. It is fabricated on a 14 nm process at GlobalFoundries, with 2,200 million transistors packed into a 103 mm² die. That yields a transistor density of 21.4 million transistors per square millimeter. The NVIDIA GeForce GTX 675MX uses the GK104 chip on Kepler architecture, from the GeForce 600M generation. It is built on a 28 nm process at TSMC, with 3,540 million transistors on a 294 mm² die, giving a density of 12.0 million transistors per square millimeter.

The process node difference is stark: 14 nm versus 28 nm, meaning the AMD part uses a much more modern manufacturing process. This explains the higher transistor density despite fewer total transistors. The AMD chip has 512 shading units, 32 texture mapping units, and 16 raster output units. The NVIDIA chip has 960 shading units, 80 texture mapping units, and 32 raster output units, nearly double in each category. However, the clock speeds differ. The RX 550X runs at a base of 1100 MHz with a boost of 1183 MHz, while the GTX 675MX has no recorded base or boost clock in the database. The memory clock also differs: the RX 550X uses 1500 MHz (6 Gbps effective), while the GTX 675MX uses 900 MHz (3.6 Gbps effective).

Pixel and texture rates reflect these differences. The RX 550X achieves 18.93 GPixel/s and 37.86 GTexel/s. The GTX 675MX achieves 13.08 GPixel/s and 52.32 GTexel/s. So the AMD card is faster at pixel fill, while the NVIDIA card is faster at texture fill, a consequence of having more TMUs. FP32 compute is close: the RX 550X delivers 1,211.4 GFLOPS, and the GTX 675MX delivers 1,255.7 GFLOPS. The AMD card also supports FP16 at 1,211.4 GFLOPS (1:1 ratio), while the NVIDIA card has no recorded FP16 performance.

API support also differs. The RX 550X supports DirectX 12 (12_0), OpenGL 4.6, and Vulkan 1.3. The GTX 675MX supports DirectX 12 (11_0), OpenGL 4.6, and Vulkan 1.2.175. The newer AMD part has a more recent DirectX feature level and a newer Vulkan version.

Specification Differences

The two cards differ in nearly every measurable specification. The AMD Radeon RX 550X has 4 GB of GDDR5 memory on a 128-bit bus, yielding 96.00 GB/s of bandwidth. The NVIDIA GeForce GTX 675MX has 2 GB of GDDR5 memory on a 256-bit bus, yielding 115.2 GB/s of bandwidth. So the NVIDIA card has less capacity but higher bandwidth due to the wider bus.

Power consumption is a major differentiator. The RX 550X has a TDP of 50 W and a suggested PSU of 250 W, with no power connectors required. The GTX 675MX has a TDP of 100 W, which is double, and no suggested PSU is listed. The slot width also differs: the RX 550X is a dual-slot card, while the GTX 675MX is an MXM module. The bus interface reflects this: the RX 550X uses PCIe 3.0 x8, while the GTX 675MX uses MXM-B (3.0).

Physical dimensions differ as well. The RX 550X has a recorded length of 145 mm (5.7 inches), while the GTX 675MX has no recorded length, height, or width. Display outputs are also different: the RX 550X has 1x DVI, 1x HDMI 2.0b, and 1x DisplayPort 1.4a, while the GTX 675MX's outputs are listed as "Portable Device Dependent," reflecting its MXM form factor for laptops.

Release dates are far apart. The GTX 675MX launched on 2012-09-30, while the RX 550X launched on 2018-12-15, a gap of over six years. The production status for both is end-of-life. The predecessor and successor lines differ: the RX 550X follows Polaris and precedes Vega, while the GTX 675MX follows GeForce 500M and precedes GeForce 700M.

FAQ

Q: Which GPU has the higher average benchmark score?

A: The AMD Radeon RX 550X has an average benchmark score of 10,481, compared to the NVIDIA GeForce GTX 675MX's 8,427. That is a 24.4% difference in favor of the AMD card.

Q: Which GPU wins the Geekbench OpenCL test?

A: The NVIDIA GeForce GTX 675MX wins with a score of 10,723, beating the AMD Radeon RX 550X's 9,662 by 9.9%.

Q: What is the memory capacity and bandwidth of each card?

A: The AMD Radeon RX 550X has 4 GB of GDDR5 memory on a 128-bit bus with 96.00 GB/s bandwidth. The NVIDIA GeForce GTX 675MX has 2 GB of GDDR5 memory on a 256-bit bus with 115.2 GB/s bandwidth.

Q: How do the process nodes compare?

A: The AMD Radeon RX 550X is fabricated on a 14 nm process at GlobalFoundries with 2,200 million transistors on a 103 mm² die. The NVIDIA GeForce GTX 675MX uses a 28 nm process at TSMC with 3,540 million transistors on a 294 mm² die.

Q: What is the TDP for each GPU?

A: The AMD Radeon RX 550X has a TDP of 50 W with a suggested PSU of 250 W. The NVIDIA GeForce GTX 675MX has a TDP of 100 W, with no suggested PSU listed.

Q: Which GPU supports newer API versions?

A: The AMD Radeon RX 550X supports DirectX 12 (12_0), OpenGL 4.6, and Vulkan 1.3. The NVIDIA GeForce GTX 675MX supports DirectX 12 (11_0), OpenGL 4.6, and Vulkan 1.2.175, so the AMD card has a newer DirectX feature level and Vulkan version.

The Verdict

The data presents a split decision. The AMD Radeon RX 550X is the better all-around performer based on its average benchmark score of 10,481, which is 24.4% higher than the GTX 675MX's 8,427. It also ranks higher at the 49th percentile versus the 43rd percentile. For general compute workloads, the RX 550X is the stronger choice.

The NVIDIA GeForce GTX 675MX is the winner in the specific OpenCL test, scoring 10,723 versus 9,662, a 9.9% advantage. If the primary workload is OpenCL-based, the GTX 675MX delivers better raw performance in that API.

Architecturally, the RX 550X is newer, built on a 14 nm process versus 28 nm, with a smaller die (103 mm² versus 294 mm²) and fewer transistors (2,200 million versus 3,540 million) but higher density (21.4M/mm² versus 12.0M/mm²). The GTX 675MX has more shading units (960 versus 512), more TMUs (80 versus 32), and more ROPs (32 versus 16), but the RX 550X has a higher pixel rate (18.93 GPixel/s versus 13.08 GPixel/s).

For memory, the RX 550X offers more capacity (4 GB versus 2 GB) but lower bandwidth (96.00 GB/s versus 115.2 GB/s). Power efficiency favors the RX 550X at 50 W TDP versus 100 W for the GTX 675MX.

The verdict depends on the use case. For users prioritizing overall compute versatility, higher average scores, newer architecture, and lower power draw, the AMD Radeon RX 550X is the recommended pick. For users specifically targeting OpenCL performance or needing the wider 256-bit memory bus, the NVIDIA GeForce GTX 675MX holds the advantage in that single recorded test. The GTX 675MX is also the only one with a Metal benchmark score (6,131), which may matter for Apple ecosystem workloads. Otherwise, the RX 550X's newer node, higher percentile rank, and 24.4% average score lead make it the data-backed choice for most scenarios.