AMD Radeon HD 8870M vs AMD Radeon R9 M375X Comparison

The AMD Radeon HD 8870M and AMD Radeon R9 M375X are two end-of-life mobile GPUs from the same manufacturer, both built on the GCN 1.0 architecture. The data shows they are remarkably close in overall performance, sharing identical core configurations and memory subsystems, with the primary differentiator being clock speeds. Benchmark results indicate the HD 8870M holds a slight edge in OpenCL performance, while the R9 M375X counters with higher raw throughput rates and a Vulkan score.

FAQ

Q: Which GPU has the higher average benchmark score?

A: The AMD Radeon HD 8870M has an average benchmark score of 8462, which is 1.6% higher than the AMD Radeon R9 M375X's average score of 8325.

Q: How do these two cards compare in OpenCL performance?

A: In the Geekbench OpenCL test, the AMD Radeon HD 8870M scores 8462, defeating the AMD Radeon R9 M375X's score of 8273 by a delta of 2.3%.

Q: Does the R9 M375X have any unique benchmark results?

A: Yes, the AMD Radeon R9 M375X has a Geekbench Vulkan score of 8377. The HD 8870M does not have a recorded Vulkan benchmark in the data.

Q: What are the core counts of these GPUs?

A: Both the AMD Radeon HD 8870M and the AMD Radeon R9 M375X feature identical core configurations: 640 shading units, 40 texture mapping units, and 16 render output units.

Q: Is there a difference in memory bandwidth between the two?

A: No, both GPUs use 2 GB of GDDR5 memory on a 128-bit bus, resulting in an identical memory bandwidth of 72.00 GB/s.

Q: Which GPU has a higher boost clock speed?

A: The AMD Radeon R9 M375X has a boost clock of 1015 MHz, which is significantly higher than the AMD Radeon HD 8870M's boost clock of 775 MHz.

Where Each One Wins

The AMD Radeon HD 8870M wins in the only direct head-to-head benchmark recorded. Its Geekbench OpenCL score of 8462 outperforms the R9 M375X's 8273, a 2.3% advantage. This suggests that for compute workloads leveraging OpenCL, the older HD 8870M is the more efficient choice despite its lower clock speeds.

The AMD Radeon R9 M375X wins in theoretical throughput metrics. Its higher clocks drive a pixel rate of 16.24 GPixel/s, a texture rate of 40.60 GTexel/s, and FP32 performance of 1,299.2 GFLOPS. These figures are all substantially higher than the HD 8870M's corresponding rates of 12.40 GPixel/s, 31.00 GTexel/s, and 992.0 GFLOPS. Furthermore, the R9 M375X has a recorded Vulkan score of 8377, a capability the HD 8870M lacks in the data.

Architecture Differences

Both GPUs are built on the same GCN 1.0 architecture and use the 28 nm process node at TSMC. They share the same transistor count of 1,500 million and an identical die size of 123 mm², yielding the same transistor density of 12.2M / mm². The silicon itself is different, however, with the HD 8870M using the Venus chip and the R9 M375X using the Tropo chip.

Both cards support the same API set, including DirectX 12 (11_1), OpenGL 4.6, and Vulkan 1.2.170. They are also both end-of-life products. The HD 8870M belongs to the Solar System generation (HD 8800M) and was succeeded by the Gem System, while the R9 M375X is part of the Gem System generation (R9 M300) and was succeeded by Polaris Mobile. The HD 8870M's predecessor was London, whereas the R9 M375X's predecessor was Solar System.

Specification Differences

The core specifications are identical for both cards: 640 shading units, 40 TMUs, 16 ROPs, 2 GB of GDDR5 memory, a 128-bit bus, 72.00 GB/s bandwidth, and a PCIe 3.0 x16 interface. The differences lie entirely in clock speeds and the resulting throughput rates.

The HD 8870M operates at a base clock of 725 MHz with a boost clock of 775 MHz. In contrast, the R9 M375X runs at a base clock of 925 MHz and boosts to 1015 MHz. This clock advantage translates directly to higher performance metrics for the R9 M375X: its pixel rate is 16.24 GPixel/s versus 12.40 GPixel/s, its texture rate is 40.60 GTexel/s versus 31.00 GTexel/s, and its FP32 compute is 1,299.2 GFLOPS versus 992.0 GFLOPS. Memory clocks are identical at 1125 MHz with 4.5 Gbps effective speed.

Head-to-Head Benchmarks

The only direct benchmark comparison available is Geekbench OpenCL. The HD 8870M scores 8462, while the R9 M375X scores 8273. This gives the HD 8870M a 2.3% lead, a modest but clear victory in raw compute performance. This is notable because the R9 M375X has significantly higher clock speeds and theoretical throughput, yet still loses in this real-world compute test.

The R9 M375X's advantage is visible in its theoretical specifications. Its FP32 performance of 1,299.2 GFLOPS is 31% higher than the HD 8870M's 992.0 GFLOPS. Similarly, its texture rate of 40.60 GTexel/s is 31% higher than the HD 8870M's 31.00 GTexel/s, and its pixel rate of 16.24 GPixel/s is 31% higher than the HD 8870M's 12.40 GPixel/s. These are substantial gaps on paper, yet they do not translate into a win in the OpenCL benchmark.

Examining the nearest rivals provides context for both GPUs' standing. The HD 8870M sits near the NVIDIA GeForce MX330 (8458, 0.1% difference) and the AMD Radeon 880M (8436, 0.3% difference). It trails the Intel Arc A380 (8558) by 1.1%. The R9 M375X, with its lower average score of 8325, is 0.7% ahead of the NVIDIA Quadro K1200 (8265) but trails 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%. Both GPUs occupy the 43rd percentile among all GPUs.

The Verdict

The data presents a clear, if counterintuitive, picture. The AMD Radeon HD 8870M is the better choice for OpenCL compute workloads. Its benchmark score of 8462 is the highest among all results for either card, and it beats the R9 M375X's OpenCL score by 2.3%. If your primary use case involves OpenCL-accelerated applications, the HD 8870M is the superior option, despite being from an older generation.

The AMD Radeon R9 M375X, however, offers the higher clock speeds and correspondingly higher theoretical throughput. Its boost clock of 1015 MHz, pixel rate of 16.24 GPixel/s, texture rate of 40.60 GTexel/s, and FP32 of 1,299.2 GFLOPS are all significantly higher than the HD 8870M's. For workloads that scale with raw fill rates or shader throughput, the R9 M375X should be the faster card, even if that advantage did not materialize in the OpenCL test. It also has a recorded Vulkan score of 8377, which is absent for the HD 8870M, making it the safer pick for Vulkan-based titles.

For a user choosing between these two, the decision hinges on the software in use. If the application is OpenCL-bound, the HD 8870M is the proven winner. For everything else, particularly graphics workloads utilizing Vulkan, the R9 M375X's higher clocks and theoretical performance make it the more compelling option. The overall average benchmark score slightly favors the HD 8870M (8462 vs 8325), but both cards are closely matched and sit at the same 43rd percentile among all GPUs.