AMD Radeon 550X vs AMD Radeon HD 8870M Comparison

The AMD Radeon 550X and AMD Radeon HD 8870M are both end-of-life mobile graphics solutions from AMD, but they represent vastly different eras of the company’s GPU architecture. The 550X is a 14 nm Polaris part built on GCN 4.0, while the HD 8870M is a 28 nm Venus chip based on the original GCN 1.0. The benchmark data shows a clear, though modest, overall victory for the newer 550X, driven by a single head-to-head result. This analysis breaks down the performance delta, architectural evolution, and the specific use cases where each card retains a niche.

Head-to-Head Benchmarks

The only direct benchmark comparison available is the Geekbench OpenCL test, and it favors the AMD Radeon 550X by a meaningful margin. The 550X scores 8866 points, while the HD 8870M scores 8462 points, yielding a delta of 4.8% in favor of the newer part. This is not a dramatic generational leap, but it is a consistent and measurable advantage in raw compute throughput.

Looking at the broader context, the 550X’s average benchmark score of 8918 places it in the 45th percentile of all GPUs. Its nearest rivals include the AMD Radeon Pro WX 5100 (avg score 8863, delta 0.6%) and the AMD Radeon R9 M265X (avg score 8851, delta 0.8%), both of which it barely edges out. Interestingly, it trails the NVIDIA GeForce GTX 660 (avg score 9022, delta -1.2%) and the NVIDIA TITAN V CEO Edition (avg score 9037, delta -1.3%), showing that the 550X sits in a competitive mid-range band.

The HD 8870M, with an average benchmark score of 8462, lands in the 43rd percentile. Its nearest rivals are tightly clustered: the NVIDIA GeForce MX330 (avg score 8458, delta 0.1%) and the AMD Radeon 880M (avg score 8436, delta 0.3%) are essentially tied with it, while the NVIDIA GeForce GTX 675MX (avg score 8427, delta 0.4%) sits just below. The only rival it clearly loses to is the Intel Arc A380 (avg score 8558, delta -1.1%). This clustering suggests the HD 8870M’s compute performance is still relevant against much newer entry-level parts, even if it is not competitive with the 550X.

The 4.8% delta in the head-to-head OpenCL test translates to a real, though not overwhelming, performance advantage for the 550X. In practical terms, this means the 550X will complete OpenCL workloads—such as video encoding, physics simulation, or general-purpose GPU compute—noticeably faster than the HD 8870M. The 550X also has a Geekbench Vulkan score of 8970, which is slightly higher than its OpenCL score, indicating that its newer architecture handles modern graphics APIs more efficiently. The HD 8870M has no Vulkan benchmark score in this data, only its OpenCL result, reinforcing that it is a product of an older API era.

Where Each One Wins

The AMD Radeon 550X wins the only head-to-head benchmark, taking the OpenCL test decisively. Its advantage stems from a combination of higher clocks and a more efficient architecture. The 550X runs at a base clock of 1082 MHz and boosts to 1218 MHz, compared to the HD 8870M’s 725 MHz base and 775 MHz boost. This clock speed advantage, coupled with the newer GCN 4.0 design, allows the 550X to achieve a higher FP32 throughput of 1,247.2 GFLOPS versus the HD 8870M’s 992.0 GFLOPS.

The 550X also has a significant memory bandwidth edge. Its GDDR5 memory runs at 1750 MHz (7 Gbps effective) across a 128-bit bus, delivering 112.0 GB/s. The HD 8870M’s memory runs at 1125 MHz (4.5 Gbps effective) on the same 128-bit bus, yielding only 72.00 GB/s. This 40 GB/s bandwidth advantage is critical for memory-bound workloads like texture-heavy gaming or large data set processing, making the 550X the clear choice for any task that relies on rapid data movement.

However, the HD 8870M is not without its own statistical strengths. It has more raw shading units (640 vs. 512) and more texture mapping units (40 vs. 32) than the 550X. In theory, this gives it a higher peak texture fill rate potential, but the data shows its texture rate is actually lower at 31.00 GTexel/s versus the 550X’s 38.98 GTexel/s. This is a direct result of the HD 8870M’s much lower clock speeds. The same applies to pixel rate: the HD 8870M manages 12.40 GPixel/s, while the 550X achieves 19.49 GPixel/s. The HD 8870M’s architectural advantage in unit counts is completely negated by its clock speed deficit.

Therefore, the HD 8870M’s “win” is purely theoretical. It has a wider SIMD configuration, but in every measurable performance metric—compute, texture, pixel, and memory bandwidth—the 550X comes out ahead. The only scenario where the HD 8870M might be preferable is in legacy software that is specifically optimized for GCN 1.0’s instruction set, but even then, the 550X’s higher clocks would likely compensate.

Architecture Differences

The architectural gap between these two GPUs is substantial, representing a full three generations of GCN evolution. The AMD Radeon 550X is built on the 14 nm process at GlobalFoundries, packing 2,200 million transistors into a 103 mm² die. The HD 8870M, in contrast, uses TSMC’s 28 nm node, with 1,500 million transistors on a larger 123 mm² die. This is a stark illustration of process node progression: the 550X fits 44% more transistors into a 16% smaller die area, giving it a transistor density of 21.4M / mm² versus the HD 8870M’s 12.2M / mm².

The 550X uses the Lexa chip and is part of the Polaris (RX 500X) generation, which is based on GCN 4.0. The HD 8870M uses the Venus chip and belongs to the Solar System (HD 8800M) generation, based on the original GCN 1.0. This architectural generation gap explains many of the performance differences. GCN 4.0 brought refinements to the shader compiler, improved geometry processing, and better power efficiency compared to the first-generation GCN.

Clock speeds are the most obvious differentiator. The 550X operates at 1082 MHz base and 1218 MHz boost, while the HD 8870M is locked to a much lower 725 MHz base and 775 MHz boost. This nearly 400 MHz difference in base clock is the primary driver of the 550X’s performance lead. The 550X also has a newer memory controller, with its GDDR5 running at 7 Gbps effective versus the HD 8870M’s 4.5 Gbps.

In terms of API support, the 550X is more future-proof. It supports DirectX 12 (12_0), OpenGL 4.6, and Vulkan 1.3. The HD 8870M also supports DirectX 12, but only at the 11_1 feature level, and its Vulkan support is older at 1.2.170. Both support OpenGL 4.6. This means the 550X can handle modern DirectX 12 titles with full feature sets, while the HD 8870M is limited to a reduced feature set. The 550X also features a PCIe 3.0 x8 interface, while the HD 8870M has a full PCIe 3.0 x16 connection, though the bandwidth difference is unlikely to matter for these performance levels.

The 550X also has a defined power profile, with a TDP of 50 W and a suggested PSU of 250 W. It is a dual-slot card with no power connectors, and it includes display outputs (1x DVI, 1x HDMI 2.0b, 1x DisplayPort 1.4a). The HD 8870M has no listed TDP, dimensions, or display outputs in the data, suggesting it was primarily designed as a mobile-only chip with flexible power characteristics.

FAQ

Q: Which GPU has a higher average benchmark score?

A: The AMD Radeon 550X has an average benchmark score of 8918, which is significantly higher than the AMD Radeon HD 8870M’s average of 8462.

Q: How does the Radeon 550X compare to its nearest rival, the NVIDIA GeForce GTX 660?

A: The Radeon 550X trails the NVIDIA GeForce GTX 660, which has an average score of 9022. The 550X’s score is 1.2% lower than the GTX 660.

Q: Does the HD 8870M have more shading units than the 550X?

A: Yes, the HD 8870M has 640 shading units, while the 550X has 512 shading units. However, the 550X’s much higher clock speeds (1082 MHz base vs. 725 MHz base) result in higher overall FP32 performance.

Q: What is the memory bandwidth of each card?

A: The Radeon 550X has a memory bandwidth of 112.0 GB/s, while the HD 8870M has a significantly lower bandwidth of 72.00 GB/s.

Q: Which GPU supports a newer version of Vulkan?

A: The Radeon 550X supports Vulkan 1.3, while the HD 8870M supports Vulkan 1.2.170.

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

A: The Radeon 550X is manufactured on a 14 nm process at GlobalFoundries, while the HD 8870M is manufactured on a 28 nm process at TSMC.

The Verdict

The data is unambiguous: the AMD Radeon 550X is the superior GPU in nearly every measurable way. It wins the only head-to-head benchmark (4.8% in OpenCL), has a higher average score (8918 vs. 8462), and sits at a higher percentile (45th vs. 43rd). Its advantages in clock speed, memory bandwidth, and process node translate directly into superior compute, pixel, and texture rates. The 550X is the clear choice for anyone needing a modern, efficient GPU that can handle OpenCL workloads and Vulkan 1.3 applications.

The AMD Radeon HD 8870M, while older and slower, is not obsolete in a statistical sense. Its average score of 8462 is within 0.1% of the NVIDIA GeForce MX330, meaning it still trades blows with entry-level modern parts. It also has more shading units and TMUs than the 550X, which could theoretically be leveraged in specific legacy applications that are not clock-sensitive. However, its lack of modern API support (DirectX 12 at 11_1 feature level) and significantly lower memory bandwidth make it a poor choice for contemporary software.

For a buyer choosing between these two, the decision is straightforward. The Radeon 550X is the better all-round performer, offering a 4.8% lead in compute, a 40 GB/s bandwidth advantage, and a more modern feature set. The HD 8870M’s only saving grace is its raw unit count, which does not translate into real-world wins in the data provided. The verdict is for the Radeon 550X, which represents a more capable and future-proof solution for general-purpose GPU computing and light gaming. The HD 8870M remains a curiosity of the GCN 1.0 era, but it is outclassed by its successor.