AMD Radeon HD 8870M vs AMD Radeon RX 6600S Comparison

FAQ

Q: How does the AMD Radeon RX 6600S compare to the AMD Radeon HD 8870M in overall benchmark performance?

A: The RX 6600S holds a decisive advantage. Its average benchmark score is 10,629, while the HD 8870M scores 8,462. The RX 6600S also sits at the 49th percentile of all GPUs, compared to the 43rd percentile for the HD 8870M.

Q: In the single available head-to-head test, what is the performance gap?

A: In the Geekbench OpenCL test, the RX 6600S scores 66,435, while the HD 8870M scores 8,462. This represents a 685.1% advantage for the RX 6600S.

Q: What are the key architectural differences between the two GPUs?

A: The RX 6600S uses the Navi 23 chip built on RDNA 2.0 architecture at a 7 nm process node. The HD 8870M uses the Venus chip based on GCN 1.0 architecture at a 28 nm node. The RX 6600S packs 11,060 million transistors versus 1,500 million for the HD 8870M.

Q: How do their memory subsystems differ?

A: The RX 6600S features 4 GB of GDDR6 memory on a 128-bit bus, delivering 224.0 GB/s of bandwidth. The HD 8870M has 2 GB of GDDR5 memory on the same 128-bit bus, but only reaches 72.00 GB/s.

Q: What is the difference in shading units and texture mapping units?

A: The RX 6600S has 1,792 shading units and 112 TMUs, while the HD 8870M has 640 shading units and 40 TMUs. The RX 6600S also includes 28 ray tracing cores, which the HD 8870M lacks entirely.

Q: Which GPU supports newer APIs?

A: The RX 6600S supports DirectX 12 Ultimate (12_2) and Vulkan 1.4, while the HD 8870M supports DirectX 12 (11_1) and Vulkan 1.2.170. Both support OpenGL 4.6.

Where Each One Wins

The data paints an overwhelmingly one-sided picture. The RX 6600S wins the only direct head-to-head benchmark, and its specifications dominate across every measurable category. The HD 8870M has no benchmark victories in the database. However, the HD 8870M does hold one contextual advantage: it was released in 2013, making it an older, lower-power design that might still be found in legacy systems. For modern workloads, the RX 6600S is categorically superior.

The RX 6600S wins in raw compute, memory bandwidth, pixel throughput, and texture processing. Its 7.168 TFLOPS of FP32 performance versus 992.0 GFLOPS for the HD 8870M means it can handle modern game engines and compute tasks with far greater ease. The HD 8870M's 12.40 GPixel/s pixel rate and 31.00 GTexel/s texture rate are dwarfed by the RX 6600S's 128.0 GPixel/s and 224.0 GTexel/s respectively. For any use case involving current-generation software, the RX 6600S is the clear pick.

Architecture Differences

The two GPUs come from entirely different eras of AMD's design philosophy. The RX 6600S uses the Navi 23 chip, built on RDNA 2.0 architecture, which represents a modern, efficient design optimized for gaming and compute workloads. It is manufactured on a 7 nm process at TSMC, allowing for a transistor density of 46.7 million per square millimeter across a 237 mm² die. The HD 8870M, by contrast, uses the Venus chip based on GCN 1.0 architecture, a design from 2013. It uses a 28 nm process, resulting in a much lower transistor density of 12.2 million per square millimeter across a 123 mm² die.

The RX 6600S includes 28 ray tracing cores, a feature entirely absent from the HD 8870M. This makes the RX 6600S compatible with modern real-time ray tracing effects in games and professional applications. The HD 8870M has no such capability. The RX 6600S also supports DirectX 12 Ultimate, which includes features like variable rate shading and mesh shaders, while the HD 8870M is limited to DirectX 12 (11_1).

The memory technology also differs significantly. The RX 6600S uses GDDR6 memory with an effective speed of 14 Gbps, while the HD 8870M uses GDDR5 with an effective speed of 4.5 Gbps. This contributes to the massive bandwidth gap: 224.0 GB/s versus 72.00 GB/s. The RX 6600S also uses a PCIe 4.0 x8 interface, while the HD 8870M uses PCIe 3.0 x16. Despite having fewer lanes, the newer PCIe standard provides more bandwidth per lane.

Specification Differences

The recorded data shows several key specification gaps between the two GPUs. The RX 6600S has a base clock of 1700 MHz and a boost clock of 2000 MHz, with a game clock of 1881 MHz. The HD 8870M runs at a base clock of 725 MHz and a boost clock of 775 MHz. This nearly threefold clock advantage for the RX 6600S translates directly into higher throughput.

Memory capacity differs: 4 GB for the RX 6600S versus 2 GB for the HD 8870M. Both use a 128-bit bus, but the RX 6600S's GDDR6 memory at 14 Gbps effective delivers 224.0 GB/s, while the HD 8870M's GDDR5 at 4.5 Gbps effective delivers only 72.00 GB/s. The RX 6600S has 1,792 shading units, 112 TMUs, and 64 ROPs, versus 640 shading units, 40 TMUs, and 16 ROPs for the HD 8870M.

The RX 6600S has a TDP of 80 W and uses an IGP slot width with no power connectors, making it suitable for integrated designs. The HD 8870M has no recorded TDP or slot width data. The RX 6600S features 28 ray tracing cores, while the HD 8870M has none. The RX 6600S supports DirectX 12 Ultimate (12_2) and Vulkan 1.4, while the HD 8870M supports DirectX 12 (11_1) and Vulkan 1.2.170.

Head-to-Head Benchmarks

The sole direct comparison in the database is the Geekbench OpenCL test, and the results are stark. The RX 6600S scores 66,435, while the HD 8870M scores 8,462. This gives the RX 6600S a 685.1% advantage, a monumental gap that reflects the generational leap in architecture and hardware resources.

Beyond the single direct test, the average benchmark scores tell a similar story. The RX 6600S averages 10,629 across all recorded benchmarks, while the HD 8870M averages 8,462. The RX 6600S's nearest rivals include the AMD Radeon R9 M275X (average score 10,582, 0.4% behind) and the NVIDIA GeForce GTX 560 Ti (average score 10,690, 0.6% ahead). This places the RX 6600S in a competitive mid-range tier for modern GPUs.

The HD 8870M's nearest rivals are notably weaker. The NVIDIA GeForce MX330 (average score 8,458, 0.1% behind), the AMD Radeon 880M (average score 8,436, 0.3% behind), and the NVIDIA GeForce GTX 675MX (average score 8,427, 0.4% behind) all cluster near its score. The Intel Arc A380 (average score 8,558, 1.1% ahead) is the only rival that surpasses it by more than a fraction of a percent.

In the recorded benchmark suite, the RX 6600S also posts individual scores across multiple tests: 66,435 in Geekbench OpenCL, 12,649 in Passmark G3D, 4,879 in Passmark GPU Compute, and 647 in Passmark G2D. It scores 176 in Passmark DirectX 9, 105 in DirectX 11, 81 in DirectX 10, and 56 in DirectX 12. The HD 8870M has only the Geekbench OpenCL result recorded.

The RX 6600S's advantage in raw specifications is reflected in its benchmark wins. Its 7.168 TFLOPS of FP32 compute, 128.0 GPixel/s pixel rate, and 224.0 GTexel/s texture rate all point to a GPU that can handle modern gaming at reasonable settings in portable devices. The HD 8870M, with 992.0 GFLOPS, 12.40 GPixel/s, and 31.00 GTexel/s, is a relic of the 2013 era, suited only to older or very lightweight workloads. The database records one win for the RX 6600S and zero for the HD 8870M, and the head-to-head data leaves no ambiguity about which GPU dominates.