AMD Radeon 550X vs AMD Radeon R9 M375X Comparison

Head-to-Head Benchmarks

The benchmark data presents a clear, though not overwhelming, victory for the AMD Radeon 550X across both tested workloads. In the Geekbench OpenCL test, the 550X scores 8866 against the R9 M375X's 8273, a decisive 7.2% advantage. The Vulkan results tell a nearly identical story: 8970 for the 550X versus 8377 for the R9 M375X, translating to a 7.1% lead. This consistency across two different API workloads suggests the performance gap is fundamental rather than workload-specific.

Examining the 550X's position among its nearest rivals provides additional context. Its average benchmark score of 8918 places it 0.6% ahead of the AMD Radeon Pro WX 5100 (8863) and 0.8% ahead of the AMD Radeon R9 M265X (8851). However, it trails the NVIDIA GeForce GTX 660 (9022) by 1.2% and the NVIDIA TITAN V CEO Edition (9037) by 1.3%. These margins are remarkably tight — the 550X sits in a performance band where single-digit percentage swings separate it from both professional workstation cards and high-end consumer parts from a previous generation.

The R9 M375X, with an average score of 8325, occupies a slightly lower tier. Its nearest rival comparisons show it 0.7% ahead of the NVIDIA Quadro K1200 (8265) but behind the NVIDIA GeForce GTX 675MX (8427) by 1.2%, the AMD Radeon 880M (8436) by 1.3%, and the NVIDIA GeForce MX330 (8458) by 1.6%. The R9 M375X's percentile ranking of 43 versus the 550X's 45 reinforces this positioning — both cards sit near the middle of the GPU performance distribution, but the 550X consistently holds a measurable edge.

Architecture Differences

The architectural divide between these two GPUs is substantial, reflecting their different generations and design philosophies. The AMD Radeon 550X is built on the Lexa chip using GCN 4.0 architecture, manufactured on a 14 nm process at GlobalFoundries. It belongs to the Polaris (RX 500X) generation. In contrast, the AMD Radeon R9 M375X uses the Tropo chip with the original GCN 1.0 architecture, fabricated on a 28 nm process at TSMC, and comes from the Gem System (R9 M300) generation.

The transistor counts and die sizes tell an interesting story about process efficiency. The 550X packs 2,200 million transistors into a 103 mm² die, achieving a transistor density of 21.4 million per square millimeter. The R9 M375X contains fewer transistors — 1,500 million — spread across a larger 123 mm² die, resulting in a much lower density of 12.2 million per square millimeter. This is a direct consequence of the 14 nm versus 28 nm process gap; the newer node allows significantly more transistors in a smaller area.

Clock speeds also favor the 550X. Its base clock runs at 1082 MHz with a boost up to 1218 MHz, while the R9 M375X operates at 925 MHz base and 1015 MHz boost. Memory clocks show an even wider divergence: the 550X runs its GDDR5 at 1750 MHz (7 Gbps effective), producing 112.0 GB/s of bandwidth over a 128-bit bus. The R9 M375X's GDDR5 runs at 1125 MHz (4.5 Gbps effective), yielding only 72.00 GB/s over the same 128-bit bus width. Both cards have 2 GB of VRAM.

The compute resources present a nuanced comparison. The R9 M375X actually has more shading units (640 vs. 512), more texture mapping units (40 vs. 32), and an identical ROP count (16). This gives it a higher texture rate of 40.60 GTexel/s versus the 550X's 38.98 GTexel/s. However, the 550X's higher clocks and newer architecture deliver superior pixel rate (19.49 GPixel/s vs. 16.24 GPixel/s) and comparable FP32 throughput (1,247.2 GFLOPS vs. 1,299.2 GFLOPS). Notably, the 550X supports FP16 at a 1:1 ratio (1,247.2 GFLOPS), while the R9 M375X has no listed FP16 capability.

API support further separates the two. The 550X supports DirectX 12 (12_0), OpenGL 4.6, and Vulkan 1.3. The R9 M375X is limited to DirectX 12 (11_1), though it matches OpenGL 4.6 and offers Vulkan 1.2.170. The 550X also has a defined power envelope at 50 W TDP with a dual-slot cooler and no power connectors, plus a suggested 250 W PSU. The R9 M375X has no TDP, slot width, or power connector data listed. The 550X connects via PCIe 3.0 x8, while the R9 M375X uses PCIe 3.0 x16.

Where Each One Wins

The AMD Radeon 550X wins in every benchmark category that the data covers. Its 7.2% OpenCL advantage and 7.1% Vulkan advantage make it the clear choice for compute-oriented workloads that leverage these APIs. The newer GCN 4.0 architecture brings better memory efficiency — the 55.6% higher memory bandwidth (112.0 GB/s vs. 72.00 GB/s) is likely a major contributor to this consistent performance edge. The 550X also benefits from significantly higher clock speeds, with a 17% higher base clock and 20% higher boost clock.

The R9 M375X does not win any benchmark comparisons in this dataset. However, it does hold theoretical advantages in specific compute metrics that may matter for certain workloads. Its higher texture rate (40.60 GTexel/s vs. 38.98 GTexel/s) and greater FP32 throughput (1,299.2 GFLOPS vs. 1,247.2 GFLOPS) suggest that raw shader-heavy tasks could potentially close the gap, even if the actual benchmark results do not reflect this. The R9 M375X's 640 shading units versus 512 for the 550X is a 25% advantage in raw ALU count, though the 550X's architectural improvements negate this in practice.

For users prioritizing API compatibility, the 550X holds a clear edge with Vulkan 1.3 support and DirectX 12 (12_0). The R9 M375X's Vulkan 1.2.170 and DirectX 12 (11_1) are older revisions that may limit access to certain modern rendering features. The 550X's FP16 support at 1:1 ratio also opens up workloads that the R9 M375X cannot efficiently handle, given its lack of listed FP16 capability.

The Verdict

The data unequivocally favors the AMD Radeon 550X. It wins both head-to-head benchmarks with margins exceeding 7%, holds a higher average benchmark score (8918 vs. 8325), and ranks higher in the overall GPU percentile distribution (45th vs. 43rd). The architectural advantages — 14 nm process, newer GCN 4.0 design, higher clocks, and substantially greater memory bandwidth — provide a foundation for this performance lead.

For users selecting between these two end-of-life GPUs, the 550X is the superior choice across every measured dimension. Its higher Vulkan score (8970) suggests better performance in modern API-driven workloads, while its OpenCL advantage (8866 vs. 8273) covers compute tasks. The 550X also offers more future-proof API support and FP16 capabilities that the R9 M375X lacks entirely.

The R9 M375X is not without merit in specific theoretical scenarios. Its higher texture rate and greater FP32 throughput could make it competitive in workloads that are heavily texture-bound or require maximum raw floating-point performance. However, the benchmark data shows that these theoretical advantages do not translate into real-world wins. The 550X's superior memory subsystem and architectural efficiency consistently overcome the R9 M375X's raw compute advantages.

For a system builder or upgrade path, the 550X's 50 W TDP and lack of power connectors make it a more flexible option for compact or lower-wattage builds, though the R9 M375X's power characteristics are not documented. Both cards are end-of-life, so availability and driver support should be considered based on individual system requirements.

FAQ

Q: Which GPU performs better in OpenCL workloads?

A: The AMD Radeon 550X scores 8866 in Geekbench OpenCL, which is 7.2% higher than the AMD Radeon R9 M375X's score of 8273.

Q: How do the two cards compare in Vulkan performance?

A: The AMD Radeon 550X achieves 8970 in Geekbench Vulkan, leading the AMD Radeon R9 M375X's 8377 by a 7.1% margin.

Q: What is the memory bandwidth difference between these GPUs?

A: The AMD Radeon 550X provides 112.0 GB/s of bandwidth, while the AMD Radeon R9 M375X delivers 72.00 GB/s — a difference of 40 GB/s in favor of the 550X.

Q: Do both cards support the same DirectX version?

A: No. The AMD Radeon 550X supports DirectX 12 (12_0), whereas the AMD Radeon R9 M375X is limited to DirectX 12 (11_1).

Q: Which GPU has more shading units?

A: The AMD Radeon R9 M375X has 640 shading units, which is 128 more than the AMD Radeon 550X's 512 shading units.

Q: What is the process node difference between the two chips?

A: The AMD Radeon 550X uses a 14 nm process at GlobalFoundries, while the AMD Radeon R9 M375X uses a 28 nm process at TSMC.