AMD Radeon RX 6600M vs NVIDIA GeForce RTX 3080 Mobile Comparison

The NVIDIA GeForce RTX 3080 Mobile and AMD Radeon RX 6600M are both end-of-life mobile graphics solutions from 2021, but they target different performance tiers. The RTX 3080 Mobile holds a decisive lead in the majority of benchmark scenarios, winning 8 out of 10 head-to-head tests, while the RX 6600M counters in two legacy and 2D-focused workloads. This analysis breaks down their architectural foundations and quantifies where each GPU demonstrates its strengths, based strictly on the provided benchmark data.

Where Each One Wins

The NVIDIA GeForce RTX 3080 Mobile is the clear winner for modern, high-load 3D rendering and compute tasks. Its victories span DirectX 12, Vulkan, OpenCL, and DirectX 11 workloads, establishing it as the superior choice for contemporary gaming and GPU-accelerated productivity. The data shows a massive 76.9% advantage in the 3DMark Steel Nomad DX12 test, a 54.7% lead in Geekbench OpenCL, and a 41.1% lead in Geekbench Vulkan. This pattern indicates the RTX 3080 Mobile is engineered for sustained performance in demanding applications that leverage current graphics APIs.

Conversely, the AMD Radeon RX 6600M wins in two specific categories: Passmark DirectX 9 and Passmark G2D. The DirectX 9 win is by a slim 7.6% margin, while the G2D (2D graphics) victory is more substantial at 12.5%. These wins suggest the RX 6600M has a slight edge in legacy API scenarios and in pure 2D rasterization throughput, which could be relevant for older games or desktop-style workloads. However, these are narrow and isolated victories; the overall performance picture heavily favors NVIDIA.

For users prioritizing frame rates in modern titles or running GPU compute tasks like OpenCL-accelerated rendering, the RTX 3080 Mobile is the unequivocal choice. The RX 6600M’s wins are niche, making it more suitable for systems where legacy API compatibility and 2D performance are prioritized over raw 3D power.

Architecture Differences

The two GPUs are built on fundamentally different architectures and process nodes. The NVIDIA GeForce RTX 3080 Mobile uses the GA104 chip based on the Ampere architecture, fabricated on an 8 nm process at Samsung. This chip contains 17,400 million transistors on a 392 mm² die, resulting in a transistor density of 44.4 million transistors per square millimeter. In contrast, the AMD Radeon RX 6600M uses the Navi 23 chip based on the RDNA 2.0 architecture, built on a more advanced 7 nm process at TSMC. It packs 11,060 million transistors on a smaller 237 mm² die, achieving a higher density of 46.7 million transistors per square millimeter.

The compute configurations diverge significantly. The RTX 3080 Mobile features 6144 shading units, 192 texture mapping units (TMUs), and 96 raster operation units (ROPs). It also includes 48 ray tracing cores and 192 tensor cores, which are specialized hardware for ray-traced lighting and AI-accelerated tasks like DLSS. The RX 6600M, by contrast, has 1792 shading units, 112 TMUs, and 64 ROPs. It includes 28 ray tracing cores but has no tensor cores, a key differentiator for AI-based features. This massive difference in shading units (6144 vs 1792) explains the RTX 3080 Mobile’s raw computational advantage.

Clock speeds and power draw also differ. The RX 6600M runs at a much higher base clock of 2068 MHz and a boost clock of 2416 MHz, with a game clock of 2177 MHz. The RTX 3080 Mobile operates at a lower base clock of 1110 MHz and a boost clock of 1545 MHz. Despite this, the RTX 3080 Mobile’s higher power envelope (115 W TDP vs 100 W TDP) allows it to feed its much larger array of cores. The RX 6600M’s higher clocks and smaller core count result in a lower peak FP32 throughput of 8.659 TFLOPS, while the RTX 3080 Mobile achieves 18.98 TFLOPS. Notably, the RX 6600M has a 2:1 FP16 ratio, delivering 17.32 TFLOPS for half-precision work, while the RTX 3080 Mobile offers 1:1 FP16 at 18.98 TFLOPS.

Head-to-Head Benchmarks

The 3DMark Steel Nomad DX12 test is the most lopsided comparison, with the RTX 3080 Mobile scoring 2644 against the RX 6600M’s 1495. This 76.9% delta underscores a generational leap in DirectX 12 performance, likely driven by the NVIDIA GPU’s superior shading unit count and texture fill rate. This is not a marginal win; it is a dominant performance class separation.

In compute-oriented benchmarks, the RTX 3080 Mobile again takes a commanding lead. In Geekbench OpenCL, it scores 104831 versus the RX 6600M’s 67765, a 54.7% advantage. The Vulkan test shows a similar trend, with the NVIDIA GPU scoring 104066 against 73740, a 41.1% lead. These results confirm that the RTX 3080 Mobile is not just a gaming GPU but also a potent compute accelerator, outpacing the AMD part in general-purpose GPU workloads.

The Passmark suite provides a mixed picture. In Passmark G3D, the RTX 3080 Mobile scores 16321 versus 13929, a 17.2% win. The gap narrows in Passmark DirectX 11, where the NVIDIA part leads by just 7.4% (146 vs 136). However, the RX 6600M takes a narrow victory in Passmark DirectX 9, scoring 184 against the RTX 3080 Mobile’s 170, a 7.6% reversal. This suggests AMD’s architecture retains stronger performance for legacy DirectX 9 titles, which can be relevant for older game libraries.

The RX 6600M also wins in Passmark G2D, scoring 728 versus 637, a 12.5% margin. This is a notable win for the AMD part in 2D rasterization, indicating it might be more responsive for desktop use or 2D applications. However, this is a minor workload compared to 3D rendering. The final significant NVIDIA win is in Passmark GPU Compute, where it scores 7276 against 5646, a 28.9% lead, further solidifying its compute superiority.

Specification Differences

The specification sheets for these two GPUs reveal several key differences beyond their core architectures. The most obvious is the process node, where AMD uses a 7 nm TSMC process versus NVIDIA’s 8 nm Samsung process. This gives the RX 6600M a smaller die (237 mm² vs 392 mm²) and lower transistor count (11,060 million vs 17,400 million), though the RX 6600M has a higher transistor density (46.7M / mm² vs 44.4M / mm²).

Memory configuration is a major differentiator. Both GPUs have 8 GB of GDDR6 memory, but the RTX 3080 Mobile uses a 256-bit memory bus, delivering a bandwidth of 448.0 GB/s. The RX 6600M is restricted to a 128-bit bus, halving the bandwidth to 224.0 GB/s. This bandwidth advantage is critical for the RTX 3080 Mobile’s performance at high resolutions and in memory-intensive textures, as it can move data twice as fast as the AMD part.

Clock speeds differ substantially. The RX 6600M has a much higher base clock (2068 MHz vs 1110 MHz) and boost clock (2416 MHz vs 1545 MHz), reflecting its more efficient 7 nm process. However, the RTX 3080 Mobile compensates with its higher core count. The TDP also differs, with the RTX 3080 Mobile rated at 115 W versus the RX 6600M’s 100 W, indicating the NVIDIA GPU draws more power to sustain its higher performance.

Other differences include the RTX 3080 Mobile’s PCIe 4.0 x16 interface versus the RX 6600M’s PCIe 4.0 x8, and the presence of 192 tensor cores on the NVIDIA GPU, which the AMD part lacks entirely. Both support DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4, so API feature support is a non-factor in this comparison.

FAQ

Q: Which GPU has a higher overall average benchmark score?

A: The NVIDIA GeForce RTX 3080 Mobile has an average benchmark score of 23628, while the AMD Radeon RX 6600M scores 23273. The RTX 3080 Mobile is slightly ahead, and both sit at a similar percentile rank (69th vs 68th among all GPUs).

Q: How much faster is the RTX 3080 Mobile in the 3DMark Steel Nomad DX12 test?

A: The RTX 3080 Mobile scores 2644, which is 76.9% higher than the RX 6600M’s 1495 score. This is the largest performance gap in the head-to-head benchmark suite.

Q: Does the AMD RX 6600M win any benchmarks against the RTX 3080 Mobile?

A: Yes, the RX 6600M wins two tests: Passmark DirectX 9 (184 vs 170, a 7.6% lead) and Passmark G2D (728 vs 637, a 12.5% lead). These wins are in legacy API and 2D performance, respectively.

Q: What is the memory bandwidth difference between the two GPUs?

A: The RTX 3080 Mobile has a 256-bit memory bus providing 448.0 GB/s of bandwidth, while the RX 6600M has a 128-bit bus providing 224.0 GB/s. The NVIDIA GPU has exactly double the memory bandwidth of the AMD part.

Q: Are there differences in ray tracing and tensor core hardware?

A: Yes. The RTX 3080 Mobile has 48 ray tracing cores and 192 tensor cores. The RX 6600M has 28 ray tracing cores but no tensor cores, meaning it lacks dedicated AI acceleration hardware that NVIDIA uses for features like DLSS.

Q: How do their compute performances compare in Geekbench OpenCL?

A: The RTX 3080 Mobile scores 104831, which is 54.7% higher than the RX 6600M’s 67765. This indicates a significant advantage for the NVIDIA GPU in OpenCL compute workloads.