AMD Radeon RX 6600S vs AMD Radeon RX 7800 XT Comparison

The AMD Radeon RX 7800 XT and AMD Radeon RX 6600S are fundamentally different products: a desktop-focused, high-performance card from the RDNA 3.0 generation versus a mobile-oriented, power-efficient chip from the RDNA 2.0 generation. The data shows a decisive overall win for the RX 7800 XT, taking 7 of 8 head-to-head benchmarks, but the RX 6600S posts a surprising single victory that reveals its distinct character. This analysis breaks down the specification gaps, benchmark results, and practical implications for each card.

The Verdict

The RX 7800 XT is the clear choice for any desktop build requiring maximum rasterization throughput. Its PassMark G3D score of 24,176 is 91.1% higher than the RX 6600S's 12,649, and it leads by even wider margins in compute-heavy workloads. The RX 6600S, by contrast, is an end-of-life mobile part (IGP form factor, 80 W TDP) that trades raw performance for portability and efficiency. Data indicates the RX 6600S wins only in Geekbench OpenCL (66,435 vs 18,290, a 72.5% advantage), which is an anomaly worth examining rather than a reason to choose it for desktop use. If you are building a desktop PC with a discrete GPU, the RX 7800 XT is the only sensible pick from this pair. If you need a low-power embedded or portable solution, the RX 6600S offers a specific niche, but its 4 GB memory and 128-bit bus limit its modern gaming viability.

FAQ

Q: Which card has more raw graphics power according to the data?

A: The RX 7800 XT dominates. Its PassMark G3D score is 24,176 versus 12,649 for the RX 6600S, a 91.1% advantage. In PassMark GPU Compute, the gap is even larger: 13,473 vs 4,879, a 176.1% lead.

Q: Why does the RX 6600S win the Geekbench OpenCL test?

A: The RX 6600S scores 66,435 in Geekbench OpenCL, while the RX 7800 XT scores 18,290. This is a 72.5% difference in favor of the RX 6600S. This likely reflects different driver optimizations or workload characteristics in that specific OpenCL benchmark, as the RX 7800 XT wins every other shared test.

Q: What is the memory capacity difference?

A: The RX 7800 XT has 16 GB of GDDR6 on a 256-bit bus, yielding 624.1 GB/s bandwidth. The RX 6600S has 4 GB of GDDR6 on a 128-bit bus, yielding 224.0 GB/s bandwidth. The 7800 XT offers four times the capacity and nearly three times the bandwidth.

Q: How do the power requirements compare?

A: The RX 7800 XT has a TDP of 263 W and requires a 600 W suggested PSU, with two 8-pin power connectors. The RX 6600S has an 80 W TDP, no power connectors (it uses the motherboard/bus power), and no suggested PSU is listed.

Q: Which card is newer?

A: The RX 7800 XT was released on September 5, 2023, and is still in Active production. The RX 6600S was released on January 3, 2022, and its production status is End-of-life.

Q: Are both cards based on the same architecture?

A: No. The RX 7800 XT uses RDNA 3.0 on a 5 nm process with the Navi 32 chip. The RX 6600S uses RDNA 2.0 on a 7 nm process with the Navi 23 chip. They share the same DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4 API support.

Architecture Differences

The two cards belong to different generations and fabrication nodes. The RX 7800 XT is built on RDNA 3.0, a 5 nm process at TSMC, with a die size of 346 mm² and 28,100 million transistors. This yields a transistor density of 81.2M per mm². The RX 6600S uses RDNA 2.0 on a 7 nm TSMC process, with a 237 mm² die and 11,060 million transistors, giving a density of 46.7M per mm². The newer node and larger die give the 7800 XT a significant architectural advantage in raw throughput.

Compute resources differ sharply. The RX 7800 XT has 3,840 shading units, 240 texture mapping units (TMUs), and 96 raster output units (ROPs), plus 60 ray tracing cores. The RX 6600S has 1,792 shading units, 112 TMUs, 64 ROPs, and 28 ray tracing cores. The 7800 XT roughly doubles the shading, texture, and ray tracing hardware. Pixel rate is 233.3 GPixel/s for the 7800 XT versus 128.0 GPixel/s for the 6600S, and texture rate is 583.2 GTexel/s versus 224.0 GTexel/s.

FP32 throughput tells the same story: 37.32 TFLOPS for the 7800 XT versus 7.168 TFLOPS for the 6600S. Notably, the FP16 ratios differ—the 7800 XT achieves 37.32 TFLOPS at a 1:1 ratio with FP32, while the 6600S achieves 14.34 TFLOPS at a 2:1 ratio. The 7800 XT also has a wider PCIe interface (x16 vs x8 for the 6600S), which matters for bandwidth-sensitive workloads.

Specification Differences

The table below highlights the key fields where the two cards differ, based strictly on the data provided.

| Specification | RX 7800 XT | RX 6600S |

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

| Architecture | RDNA 3.0 | RDNA 2.0 |

| Process Node | 5 nm | 7 nm |

| Transistors | 28,100 million | 11,060 million |

| Die Size | 346 mm² | 237 mm² |

| Base Clock | 1295 MHz | 1700 MHz |

| Boost Clock | 2430 MHz | 2000 MHz |

| Game Clock | 2124 MHz | 1881 MHz |

| Memory Speed | 2438 MHz (19.5 Gbps effective) | 1750 MHz (14 Gbps effective) |

| Memory Size | 16 GB | 4 GB |

| Memory Bus | 256 bit | 128 bit |

| Bandwidth | 624.1 GB/s | 224.0 GB/s |

| Shading Units | 3840 | 1792 |

| TMUs | 240 | 112 |

| ROPs | 96 | 64 |

| Ray Tracing Cores | 60 | 28 |

| FP32 Performance | 37.32 TFLOPS | 7.168 TFLOPS |

| TDP | 263 W | 80 W |

| Slot Width | Dual-slot | IGP |

| Power Connectors | 2x 8-pin | None |

| Suggested PSU | 600 W | None |

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

| Display Outputs | 1x HDMI 2.1a, 3x DisplayPort 2.1 | Portable Device Dependent |

| Production Status | Active | End-of-life |

| Release Date | 2023-09-05 | 2022-01-03 |

| Launch MSRP | 499 USD | None |

Head-to-Head Benchmarks

The RX 7800 XT wins 7 of 8 shared benchmarks, and the margins are consistently large. In PassMark DirectX 11, the 7800 XT scores 249 versus 105 for the 6600S, a 137.1% advantage. DirectX 12 shows a 66.1% lead (93 vs 56). DirectX 9 is 72.7% ahead (304 vs 176), and DirectX 10 is 49.4% ahead (121 vs 81).

The biggest gap appears in PassMark GPU Compute: 13,473 vs 4,879, a 176.1% difference. This indicates the 7800 XT is far better suited for general-purpose compute tasks like rendering or machine learning inference. In PassMark G3D, the 7800 XT's 24,176 score beats the 6600S's 12,649 by 91.1%, which is the most representative overall gaming performance metric here.

The 2D performance gap is also notable: PassMark G2D shows 1,177 for the 7800 XT versus 647, an 81.9% lead. The only benchmark where the RX 6600S wins is Geekbench OpenCL, where it scores 66,435 versus 18,290 for the 7800 XT—a 72.5% difference. This is a striking outlier given the 7800 XT's superior hardware. It suggests either a driver quirk or that Geekbench's OpenCL workload favors the 6600S's specific clock behavior (its base clock is 1700 MHz, higher than the 7800 XT's 1295 MHz).

Where Each One Wins

AMD Radeon RX 7800 XT wins in every practical desktop scenario. Its 16 GB memory and 624.1 GB/s bandwidth make it viable for high-resolution gaming and texture-heavy workloads, while its 60 ray tracing cores and 37.32 TFLOPS FP32 performance handle modern DirectX 12 Ultimate titles. The data shows decisive wins in all PassMark DirectX tests and in GPU compute, making it the choice for gaming, content creation, and compute tasks. Its Active production status and 2023 release date mean it is a current product with ongoing driver support. The 91.1% lead in G3D and 176.1% lead in compute are the strongest arguments in its favor.

AMD Radeon RX 6600S wins only in the Geekbench OpenCL benchmark, but that does not translate to general-purpose superiority. Its 80 W TDP and IGP form factor mean it can be integrated into portable devices without discrete power connectors, which is its primary advantage. The 4 GB memory and 224.0 GB/s bandwidth are sufficient for lightweight tasks, and its higher base clock (1700 MHz) may help in bursty, low-power workloads. However, its End-of-life status and 2022 release date indicate it is a legacy part. The data does not support using it for demanding gaming or compute, but for a low-power, embedded, or mobile application where the 7800 XT physically cannot fit, the 6600S retains a niche. Its 49th percentile versus all GPUs (compared to the 7800 XT's 51st) confirms it sits just below its bigger sibling in overall standing, despite the OpenCL anomaly.