AMD Radeon RX 580 2048SP vs AMD Radeon RX 6600M Comparison

# AMD Radeon RX 6600M vs AMD Radeon RX 580 2048SP

The benchmark data presents a decisive generational gap between these two AMD GPUs. The RX 6600M, built on RDNA 2.0, wins all three head-to-head comparisons by substantial margins, with deltas ranging from 76.1% to 128.4%. Both cards sit at the 68th percentile among all GPUs in the database, yet their average benchmark scores tell a different story: the RX 6600M averages 23,273 points while the RX 580 2048SP averages 23,061. This narrow overall gap, despite the massive per-test differences, suggests the RX 580 2048SP benefits from a wider pool of benchmark results that dilute its weaknesses.

Head-to-Head Benchmarks

The 3DMark Steel Nomad DX12 test reveals the most moderate gap between the two. The RX 6600M scores 1,495 points against the RX 580 2048SP's 849, producing a 76.1% advantage. This is a significant lead, but it represents the closest contest in the head-to-head set. The newer architecture's advantage in DirectX 12 workloads is clear, yet the older GCN card remains somewhat competitive in this specific workload.

The Geekbench OpenCL results show a far more lopsided contest. The RX 6600M posts 67,765 points, which is 128.4% higher than the RX 580 2048SP's 29,668. This more than doubles the older card's compute throughput in OpenCL, a massive generational leap. The RX 6600M's RDNA 2.0 architecture handles general-purpose compute tasks with far greater efficiency than the aging GCN 4.0 design.

Geekbench Vulkan tells a similar story, with the RX 6600M scoring 73,740 points versus 38,666 for the RX 580 2048SP, a 90.7% improvement. This near-doubling of Vulkan performance indicates that the newer architecture extracts substantially more performance from modern graphics APIs. The RX 6600M's 28 dedicated ray tracing cores and DirectX 12 Ultimate support contribute to its API-level superiority, though the benchmark itself doesn't specifically test ray tracing.

Where Each One Wins

The RX 6600M wins every benchmark where both cards have results, making its case straightforward. Its 8.659 TFLOPS FP32 compute throughput versus 5.259 TFLOPS for the RX 580 2048SP gives it a 64.7% raw compute advantage. The texture rate of 270.6 GTexel/s versus 164.4 GTexel/s further reinforces its dominance in texture-heavy workloads. For modern games and compute applications that leverage DirectX 12 Ultimate or Vulkan, the RX 6600M is clearly the superior choice.

The RX 580 2048SP, despite losing all head-to-head tests, does retain advantages in specific technical areas. Its 256-bit memory bus doubles the RX 6600M's 128-bit interface, though both achieve identical 224.0 GB/s bandwidth. The older card also has more shading units (2,048 vs 1,792) and more texture mapping units (128 vs 112), suggesting it could theoretically excel in older workloads that scale with raw shader count rather than architectural efficiency. Its PCIe 3.0 x16 interface provides more lanes than the RX 6600M's PCIe 4.0 x8, which could matter in bandwidth-sensitive scenarios, though the newer standard's higher per-lane throughput likely negates this.

The RX 580 2048SP's 1:1 FP16 ratio (5.259 TFLOPS) versus the RX 6600M's 2:1 ratio (17.32 TFLOPS) presents an interesting trade-off. The older card maintains consistent precision across FP16 and FP32, while the newer card sacrifices precision for speed. Applications requiring FP16 accuracy might theoretically prefer the RX 580 2048SP, though the RX 6600M's raw speed advantage likely outweighs this in practice.

Architecture Differences

The architectural gap between these two GPUs spans four generations of AMD design philosophy. The RX 6600M uses the Navi 23 chip on TSMC's 7 nm process, packing 11,060 million transistors into a 237 mm² die. The RX 580 2048SP uses the Polaris 20 chip on GlobalFoundries' 14 nm process, with 5,700 million transistors on a 232 mm² die. The RX 6600M achieves 46.7 million transistors per square millimeter versus 24.6 million for the RX 580 2048SP, nearly doubling transistor density.

RDNA 2.0 introduces hardware ray tracing through 28 dedicated RT cores, a feature entirely absent from the GCN 4.0-based RX 580 2048SP. The newer architecture also supports DirectX 12 Ultimate (12_2) versus DirectX 12 (12_0) for the older card, along with Vulkan 1.4 versus 1.3. These API differences translate directly into the benchmark gaps observed, as newer API features enable more efficient rendering paths.

Clock speeds reveal another major divergence. The RX 6600M operates at a 2,068 MHz base clock and 2,416 MHz boost, while the RX 580 2048SP runs at 1,168 MHz base and 1,284 MHz boost. This near-doubling of clock speed, combined with architectural efficiency gains, explains how fewer shading units (1,792 vs 2,048) can deliver vastly higher performance. The RX 6600M's pixel rate of 154.6 GPixel/s versus 41.09 GPixel/s for the RX 580 2048SP reflects both higher clocks and better ROP efficiency.

Memory technology also differs significantly. The RX 6600M uses 8 GB of GDDR6 at 14 Gbps effective, while the RX 580 2048SP uses 4 GB of GDDR5 at 7 Gbps. Despite identical 224.0 GB/s bandwidth, the newer card doubles VRAM capacity, enabling higher-resolution textures and larger working sets. The RX 6600M's power efficiency is notable: 100 W TDP versus 150 W for the RX 580 2048SP, despite delivering substantially higher performance.

FAQ

Q: Which GPU has better raw compute performance?

A: The RX 6600M delivers 8.659 TFLOPS FP32 versus 5.259 TFLOPS for the RX 580 2048SP, a 64.7% advantage. In FP16, the RX 6600M reaches 17.32 TFLOPS (2:1 ratio) while the RX 580 2048SP manages 5.259 TFLOPS (1:1 ratio).

Q: Do both GPUs support ray tracing?

A: No. The RX 6600M includes 28 dedicated ray tracing cores as part of its RDNA 2.0 architecture. The RX 580 2048SP has no ray tracing hardware, as GCN 4.0 predates AMD's ray tracing implementation.

Q: How do their memory subsystems compare?

A: Both achieve 224.0 GB/s bandwidth, but through different configurations. The RX 6600M uses 8 GB of GDDR6 on a 128-bit bus at 14 Gbps effective. The RX 580 2048SP uses 4 GB of GDDR5 on a 256-bit bus at 7 Gbps. The RX 6600M doubles VRAM capacity while using half the bus width.

Q: Which card is more power-efficient?

A: The RX 6600M has a 100 W TDP versus 150 W for the RX 580 2048SP. This 33% power reduction comes despite the RX 6600M delivering significantly higher performance, reflecting the efficiency gains of RDNA 2.0 on 7 nm versus GCN 4.0 on 14 nm.

Q: What are the interface differences?

A: The RX 6600M uses PCIe 4.0 x8, while the RX 580 2048SP uses PCIe 3.0 x16. The newer standard's higher per-lane bandwidth means the x8 configuration can potentially match or exceed the older x16 link's throughput.

Q: Which GPU has better API support?

A: The RX 6600M supports DirectX 12 Ultimate (12_2) and Vulkan 1.4, while the RX 580 2048SP supports DirectX 12 (12_0) and Vulkan 1.3. Both support OpenGL 4.6.

Specification Differences

| Specification | AMD Radeon RX 6600M | AMD Radeon RX 580 2048SP |

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

| Architecture | RDNA 2.0 | GCN 4.0 |

| Process Node | 7 nm (TSMC) | 14 nm (GlobalFoundries) |

| Transistors | 11,060 million | 5,700 million |

| Die Size | 237 mm² | 232 mm² |

| Transistor Density | 46.7M / mm² | 24.6M / mm² |

| Base Clock | 2068 MHz | 1168 MHz |

| Boost Clock | 2416 MHz | 1284 MHz |

| Memory Size | 8 GB GDDR6 | 4 GB GDDR5 |

| Memory Bus | 128 bit | 256 bit |

| Memory Speed | 14 Gbps effective | 7 Gbps effective |

| Shading Units | 1792 | 2048 |

| TMUs | 112 | 128 |

| ROPs | 64 | 32 |

| RT Cores | 28 | None |

| Pixel Rate | 154.6 GPixel/s | 41.09 GPixel/s |

| Texture Rate | 270.6 GTexel/s | 164.4 GTexel/s |

| FP32 | 8.659 TFLOPS | 5.259 TFLOPS |

| FP16 | 17.32 TFLOPS (2:1) | 5.259 TFLOPS (1:1) |

| TDP | 100 W | 150 W |

| Slot Width | IGP | Dual-slot |

| Power Connectors | None | 1x 8-pin |

| Suggested PSU | None listed | 450 W |

| Bus Interface | PCIe 4.0 x8 | PCIe 3.0 x16 |

| DirectX | 12 Ultimate (12_2) | 12 (12_0) |

| Vulkan | 1.4 | 1.3 |

| Release Date | 2021-05-30 | 2018-10-14 |

| Predecessor | Polaris Mobile | Arctic Islands |

| Successor | None | Vega |

The Verdict

The data makes a compelling case for the RX 6600M as the superior GPU in nearly every measurable way. It wins all three head-to-head benchmarks with deltas from 76.1% to 128.4%, doubles the FP32 compute throughput, offers hardware ray tracing, and does so at a lower TDP. The 7 nm process node and RDNA 2.0 architecture represent a fundamental leap over the 14 nm GCN 4.0 design. For anyone building a system around modern APIs like DirectX 12 Ultimate or Vulkan 1.4, the RX 6600M is the clear choice.

The RX 580 2048SP retains relevance only in specific legacy scenarios. Its larger memory bus (256-bit) and higher shader count (2,048) suggest it might handle older, shader-bound workloads competitively, though no benchmark data confirms this. Its 4 GB VRAM capacity limits modern gaming at higher resolutions and texture quality settings. The card's release in 2018 and end-of-life status place it firmly in a previous generation.

The average benchmark scores place these GPUs nearly equal (23,273 vs 23,061), but this masks the RX 6600M's dominance in modern workloads. The RX 580 2048SP's inclusion of PassMark DirectX 9, 10, and 11 results in its benchmark set likely inflates its overall average, as these legacy tests favor its simpler architecture. Users running modern games or compute applications should choose the RX 6600M without hesitation. Users constrained to older DirectX 9 or 10 titles, or those requiring the broader 256-bit memory interface, may find the RX 580 2048SP acceptable, though the data offers little evidence of its superiority in any measurable test.