AMD Radeon R9 M275X vs AMD Radeon R9 M375 Comparison

The AMD Radeon R9 M275X and AMD Radeon R9 M375 are two mobile graphics solutions from the same GCN 1.0 family, but they target different performance tiers. The data shows a clear, though not overwhelming, advantage for the older M275X in raw compute benchmarks, despite the M375 having higher clock speeds. This analysis breaks down the benchmark results, architectural differences, and the practical implications for each GPU based strictly on the provided facts.

Head-to-Head Benchmarks

The head-to-head results are the most direct comparison, and the AMD Radeon R9 M275X wins both tests. In the Geekbench OpenCL test, the M275X scores 11,200 points against the M375’s 10,457 points, a delta of 7.1%. This is a significant margin in synthetic compute workloads, suggesting the M275X has a clear edge in general-purpose GPU compute. The margin narrows in the Geekbench Vulkan test, where the M275X scores 9,964 versus 9,682, a smaller 2.9% lead. This indicates that while the M275X is still faster, the performance gap tightens under a modern graphics API.

The average benchmark score reinforces this hierarchy. The M275X averages 10,582 points, while the M375 averages 10,070 points. This places the M275X in the 49th percentile of all GPUs, with the M375 just behind at the 48th percentile. The M275X’s nearest rival in the data is the AMD Radeon RX 6600S, which scores 10,629, a negligible 0.4% difference. This means the M275X is effectively performance-equivalent to a much newer discrete GPU. On the other side, the M375’s closest competitor is the NVIDIA Quadro K5100M, which scores 10,043, just 0.3% behind. The context from these rivals shows both cards are firmly in the mid-range of the database’s performance spectrum, but the M275X sits at the top of that range.

Looking at the wins, the M275X takes both benchmark tests, giving it a 2-0 record. The M375 has no wins. The biggest win for the M275X is the OpenCL test, where its 7.1% lead is more than double the margin seen in Vulkan. This suggests that the M275X’s advantage is more pronounced in compute-heavy tasks that rely on raw shader throughput rather than in gaming workloads that might be more dependent on memory bandwidth and API optimization.

Architecture Differences

Both GPUs are built on the same fundamental architecture: GCN 1.0 on a 28 nm process at TSMC. They share the same transistor count of 1,500 million on a 123 mm² die, resulting in the same transistor density of 12.2M per mm². The core configurations are identical as well: 640 shading units, 40 texture mapping units, and 16 ROPs. This means the raw compute resources are the same on paper.

The key differences lie in clock speeds and memory. The AMD Radeon R9 M375 runs its core at a base clock of 1000 MHz and a boost clock of 1015 MHz, which is notably higher than the M275X’s 900 MHz base and 925 MHz boost. This higher clock speed gives the M375 a theoretical advantage in pixel rate (16.24 GPixel/s vs 14.80 GPixel/s), texture rate (40.60 GTexel/s vs 37.00 GTexel/s), and FP32 compute (1,299.2 GFLOPS vs 1,184.0 GFLOPS). The M375 is the more powerful processor on paper.

However, the memory subsystem tells a different story. The M275X uses 2 GB of GDDR5 memory on a 128-bit bus, running at 1125 MHz with an effective data rate of 4.5 Gbps. This yields a memory bandwidth of 72.00 GB/s. The M375 also has 2 GB of memory on a 128-bit bus, but it uses DDR3 at a much lower 900 MHz effective rate of 1800 Mbps. This results in a bandwidth of just 28.80 GB/s, which is less than half of the M275X’s bandwidth. This massive memory bandwidth deficit is the most significant architectural difference and likely explains why the M375’s higher core clocks do not translate into benchmark wins. The M275X’s GDDR5 memory provides 43.20 GB/s more bandwidth, which is crucial for feeding the 640 shading units.

Both cards support the same API level: DirectX 12 (11_1), OpenGL 4.6, and Vulkan 1.2.170. They also share the same PCIe 3.0 x16 bus interface. The M275X is from the R9 M200 generation, while the M375 is from the R9 M300 generation, but both are classified under the same "Gem System" series. The M275X was released earlier, and both are now end-of-life products.

The Verdict

From a pure performance standpoint, the AMD Radeon R9 M275X is the superior GPU. It wins both benchmark tests, and its average score of 10,582 is 5.1% higher than the M375’s 10,070. The M275X’s advantage is most pronounced in OpenCL, where it leads by 7.1%. The data suggests that the M275X’s use of GDDR5 memory with 72.00 GB/s bandwidth is a decisive factor, outweighing the M375’s higher core clocks. The M375’s DDR3 memory at 28.80 GB/s creates a bottleneck that prevents its theoretical compute advantage from being realized in practice.

The M275X’s placement in the performance percentile is also slightly better, at 49th versus the M375’s 48th. Considering the M275X’s closer performance to the RX 6600S (a 0.4% difference) and the M375’s similarity to the Quadro K5100M, the M275X is the card to pick for any workload where compute performance is the priority. The M375 is not a bad card, but it is clearly a step down in real-world performance.

For a user deciding between these two, the data is unambiguous: choose the M275X. The only scenario where the M375 might be preferable is if the higher core clocks are somehow beneficial for a specific task, but the benchmark results do not support that conclusion. The M275X wins in both OpenCL and Vulkan, which are representative of general compute and graphics workloads. There is no benchmark data showing the M375 winning any test, so the M275X is the recommended choice based on the available facts.

FAQ

Q: Which GPU has a higher average benchmark score?

A: The AMD Radeon R9 M275X has a higher average benchmark score of 10,582, compared to the AMD Radeon R9 M375’s 10,070.

Q: How large is the performance difference in the Geekbench OpenCL test?

A: The M275X scores 11,200, which is 7.1% higher than the M375’s 10,457 in the Geekbench OpenCL test.

Q: Do both GPUs have the same number of shading units?

A: Yes, both the AMD Radeon R9 M275X and the AMD Radeon R9 M375 feature 640 shading units.

Q: What is the key memory difference between the two cards?

A: The M275X uses 2 GB of GDDR5 memory with a bandwidth of 72.00 GB/s, while the M375 uses 2 GB of DDR3 memory with a bandwidth of 28.80 GB/s.

Q: Which GPU has a higher boost clock speed?

A: The AMD Radeon R9 M375 has a higher boost clock of 1015 MHz, compared to the M275X’s 925 MHz boost clock.

Q: Are both GPUs based on the same architecture?

A: Yes, both the AMD Radeon R9 M275X and the AMD Radeon R9 M375 are based on the GCN 1.0 architecture and are manufactured on a 28 nm process.

Where Each One Wins

Based on the benchmark data, the AMD Radeon R9 M275X is the clear winner in both tested workloads. It wins the Geekbench OpenCL test and the Geekbench Vulkan test, giving it a 2-0 record. This suggests it is better suited for general-purpose compute tasks as well as graphics rendering under modern APIs. Its superiority is likely due to its much higher memory bandwidth, which allows its 640 shading units to be fed data more effectively.

The AMD Radeon R9 M375, despite having higher core clocks and a higher theoretical FP32 throughput, does not win any benchmark. Its performance is hampered by its DDR3 memory, which provides less than half the bandwidth of the M275X’s GDDR5. However, the M375 is not without its own merits. Its higher pixel rate of 16.24 GPixel/s and texture rate of 40.60 GTexel/s could theoretically benefit tasks that are not memory-bandwidth limited, such as certain pixel-pushing operations. But the data shows that in the two benchmarks available, these advantages do not translate into a win.

For specific use cases, the M275X is the choice for OpenCL compute workloads, as evidenced by its 7.1% lead. It is also the better option for Vulkan-based applications, holding a 2.9% advantage. The M375’s higher clock speeds might make it a candidate for overclocking or specific niche workloads, but no benchmark data supports this. Therefore, the M275X wins in every category where data is available.

Specification Differences

The table below highlights the key specification differences between the two GPUs.

| Specification | AMD Radeon R9 M275X | AMD Radeon R9 M375 |

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

| Generation | Gem System (R9 M200) | Gem System (R9 M300) |

| Chip | Venus | Tropo |

| Base Clock | 900 MHz | 1000 MHz |

| Boost Clock | 925 MHz | 1015 MHz |

| Memory Clock | 1125 MHz (4.5 Gbps effective) | 900 MHz (1800 Mbps effective) |

| Memory Type | GDDR5 | DDR3 |

| Memory Bandwidth | 72.00 GB/s | 28.80 GB/s |

| Pixel Rate | 14.80 GPixel/s | 16.24 GPixel/s |

| Texture Rate | 37.00 GTexel/s | 40.60 GTexel/s |

| FP32 Performance | 1,184.0 GFLOPS | 1,299.2 GFLOPS |

| Release Date | 2014-01-27 | 2015-05-04 |

The two cards share identical core counts (640 shading units, 40 TMUs, 16 ROPs), the same 2 GB memory size and 128-bit bus, and the same process node and die size. The main differences are the memory type and bandwidth, which are drastically in favor of the M275X, and the core clocks, which are higher on the M375. The M375’s higher clocks give it superior theoretical pixel, texture, and FP32 rates, but the M275X’s superior memory bandwidth wins the real-world benchmarks.