AMD Radeon RX 6600M vs AMD Radeon RX 7800M Comparison

Where Each One Wins

The recorded data splits cleanly between these two mobile graphics solutions. The AMD Radeon RX 7800M wins 9 of the 10 head-to-head benchmark comparisons, while the AMD Radeon RX 6600M takes a single victory. That lone win comes in Passmark DirectX 9, where the RX 6600M scores 184 against the RX 7800M's 174, a 5.4% edge. For legacy DirectX 9 workloads, the older architecture holds a small advantage.

Everywhere else, the RX 7800M dominates. The largest gaps appear in modern API and compute tests. In 3DMark Steel Nomad DX12, the RX 7800M scores 2994 versus 1495 for the RX 6600M, a 100.3% improvement, meaning it more than doubles the RX 6600M's result. Geekbench Vulkan shows a 71.8% lead (126668 vs 73740), and Geekbench OpenCL shows 78.2% (120778 vs 67765). Passmark DirectX 12 also favors the RX 7800M by 71.2% (89 vs 52). The compute-oriented Passmark GPU Compute test gives the RX 7800M a 65.5% advantage (9342 vs 5646).

For general 3D rendering, Passmark G3D puts the RX 7800M at 17613 versus 13929, a 26.4% lead. Passmark DirectX 11 shows a 29.4% gap (176 vs 136), and DirectX 10 shows 13.8% (99 vs 87). The 2D test, Passmark G2D, also goes to the RX 7800M with 892 versus 728, a 22.5% margin.

Use-case interpretation: if you are running modern DX12 or Vulkan titles, the RX 7800M is in a different class. If you are stuck on older DX9 games, the RX 6600M is marginally faster, but the difference is small in absolute terms.

Architecture Differences

The two GPUs come from different architectural generations. The RX 7800M uses RDNA 3.0, built on TSMC's 5 nm process, with the Navi 32 chip and the codename "Wheat Nas." The RX 6600M uses RDNA 2.0, built on TSMC's 7 nm process, with the Navi 23 chip and no listed codename. The process node shift is significant: 5 nm vs 7 nm accounts for much of the efficiency and density gap.

Transistor counts tell the story. The RX 7800M packs 28,100 million transistors on a 346 mm² die, giving a transistor density of 81.2M per mm². The RX 6600M has 11,060 million transistors on a 237 mm² die, with a density of 46.7M per mm². The RX 7800M has roughly 2.5 times the transistor count and nearly double the density.

The compute resources differ proportionally. The RX 7800M has 3840 shading units, 240 texture mapping units, 96 render output units, and 60 ray tracing cores. The RX 6600M has 1792 shading units, 112 TMUs, 64 ROPs, and 28 RT cores. Every resource category is roughly doubled on the RX 7800M, except ROPs which are 1.5 times higher.

The FP16 execution also differs. The RX 7800M runs FP16 at 35.87 TFLOPS with a 1:1 ratio to FP32 (also 35.87 TFLOPS). The RX 6600M runs FP16 at 17.32 TFLOPS with a 2:1 ratio, meaning its FP16 throughput is double its FP32 rate of 8.659 TFLOPS. For mixed-precision workloads, the RX 7800M's 1:1 ratio is a notable architectural choice.

Both support DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. Neither has tensor cores listed. The RX 7800M uses a PCIe 4.0 x16 interface, while the RX 6600M uses PCIe 4.0 x8. Both are IGP slot width with no power connectors, and both have display outputs listed as "Portable Device Dependent."

Head-to-Head Benchmarks

The biggest single win for the RX 7800M is in 3DMark Steel Nomad DX12. The score of 2994 versus 1495 is a 100.3% delta, so the RX 7800M delivers double the performance in this modern DX12 workload. This is the clearest indicator of generational improvement.

Geekbench OpenCL shows the RX 7800M at 120778 versus 67765, a 78.2% lead. This test stresses raw compute throughput, and the RX 7800M's higher shading unit count and FP32 rate (35.87 TFLOPS vs 8.659 TFLOPS) explain the gap. Geekbench Vulkan follows a similar pattern: 126668 vs 73740, a 71.8% delta.

Passmark DirectX 12 gives the RX 7800M an 89 versus 52 score, a 71.2% advantage. The RX 7800M's DX12 path is substantially more capable. Passmark GPU Compute shows 9342 vs 5646, a 65.5% delta, reinforcing the compute advantage.

The mid-tier wins are smaller but consistent. Passmark DirectX 11: 176 vs 136, a 29.4% lead. Passmark G3D: 17613 vs 13929, a 26.4% lead. Passmark G2D: 892 vs 728, a 22.5% lead. Passmark DirectX 10: 99 vs 87, a 13.8% lead.

The RX 6600M's only win is in Passmark DirectX 9: 184 vs 174, a 5.4% delta. This is a narrow margin and likely reflects driver optimization for legacy APIs on RDNA 2.0 rather than a fundamental performance advantage.

Specification Differences

The two GPUs differ across every major specification field. The RX 7800M uses a 5 nm process; the RX 6600M uses 7 nm. The RX 7800M has 28,100 million transistors on a 346 mm² die; the RX 6600M has 11,060 million on 237 mm². Transistor density is 81.2M per mm² versus 46.7M per mm².

Clock speeds differ notably. The RX 7800M has a base clock of 1295 MHz, a boost of 2335 MHz, and a game clock of 2145 MHz. The RX 6600M has a higher base clock of 2068 MHz, a boost of 2416 MHz, and a game clock of 2177 MHz. The RX 6600M runs at higher frequencies, but the RX 7800M compensates with far more compute units. Memory clocks also differ: 2250 MHz (18 Gbps effective) for the RX 7800M versus 1750 MHz (14 Gbps effective) for the RX 6600M.

Memory configuration is a major split. The RX 7800M has 12 GB GDDR6 on a 192-bit bus, delivering 432.0 GB/s bandwidth. The RX 6600M has 8 GB GDDR6 on a 128-bit bus, delivering 224.0 GB/s. The RX 7800M has nearly double the bandwidth and 50% more capacity.

Pixel and texture rates follow the resource counts. The RX 7800M achieves 224.2 GPixel/s and 560.4 GTexel/s. The RX 6600M achieves 154.6 GPixel/s and 270.6 GTexel/s. FP32 throughput is 35.87 TFLOPS versus 8.659 TFLOPS, a 4.1 times difference.

Power draw also differs: the RX 7800M has a TDP of 180 W, while the RX 6600M has a TDP of 100 W. Both are IGP slot width with no power connectors. The RX 7800M is listed as Active production status; the RX 6600M is End-of-life. The RX 7800M released on 2024-09-10; the RX 6600M released on 2021-05-30. Both have the same predecessor (Polaris Mobile) and no successor.

FAQ

Q: Which GPU is faster in modern DirectX 12 games?

A: The AMD Radeon RX 7800M. In 3DMark Steel Nomad DX12 it scores 2994 against 1495 for the RX 6600M, a 100.3% advantage. Passmark DirectX 12 also favors the RX 7800M at 89 versus 52, a 71.2% lead.

Q: Does the RX 6600M win any benchmark?

A: Yes, one. In Passmark DirectX 9, the RX 6600M scores 184 against the RX 7800M's 174, a 5.4% margin. This is the only head-to-head win for the RX 6600M out of 10 tests.

Q: How does memory bandwidth compare?

A: The RX 7800M has 432.0 GB/s bandwidth from 12 GB GDDR6 on a 192-bit bus. The RX 6600M has 224.0 GB/s from 8 GB GDDR6 on a 128-bit bus. The RX 7800M provides roughly 93% more bandwidth.

Q: What is the compute performance difference?

A: The RX 7800M delivers 35.87 TFLOPS FP32 versus 8.659 TFLOPS for the RX 6600M. In Geekbench OpenCL, the RX 7800M scores 120778 versus 67765, a 78.2% lead. Passmark GPU Compute shows 9342 versus 5646, a 65.5% delta.

Q: Are these GPUs the same architecture?

A: No. The RX 7800M uses RDNA 3.0 on TSMC 5 nm with the Navi 32 chip. The RX 6600M uses RDNA 2.0 on TSMC 7 nm with the Navi 23 chip. The RX 7800M also has a 1:1 FP16 to FP32 ratio, while the RX 6600M has a 2:1 ratio.

Q: Which GPU has more ray tracing cores?

A: The RX 7800M has 60 ray tracing cores. The RX 6600M has 28. This is a 2.1 times difference in RT core count.

The Verdict

The data points to a clear hierarchy. The AMD Radeon RX 7800M is the stronger mobile GPU in nearly every measurable category. It wins 9 of 10 benchmarks, with an average benchmark score of 27883 compared to 23273 for the RX 6600M. The percentile ranking also favors the RX 7800M: 73rd percentile against all GPUs versus 68th for the RX 6600M.

The RX 7800M's nearest rivals in the database are the AMD Radeon Pro Vega 20 (0.2% ahead), AMD Radeon Pro W5500X (0.3% behind), NVIDIA GeForce GTX 980 Ti (0.5% behind), and AMD FirePro S7150 (0.8% behind). It sits in a tight cluster of desktop-class cards from previous generations. The RX 6600M's nearest rivals are the AMD Radeon R9 M290X (0% delta), AMD Radeon Pro Vega 16 (0.1% ahead), NVIDIA P106-100 (0.1% ahead), and AMD Radeon AI PRO R9700 (0.2% behind). These are older or lower-tier parts.

For a new laptop purchase, the RX 7800M is the obvious choice if modern gaming and compute workloads matter. Its 100.3% lead in 3DMark Steel Nomad DX12 and 71.8% lead in Geekbench Vulkan mean it will handle current and near-future titles at much higher settings. The 12 GB memory and 432.0 GB/s bandwidth also provide more headroom for high-resolution textures and VR workloads.

The RX 6600M remains relevant only for legacy DirectX 9 scenarios, where its 5.4% advantage in that single test might matter. It also draws 100 W versus 180 W, so in a power-constrained chassis it could be the more efficient option, though the performance gap is massive. The RX 6600M is end-of-life, while the RX 7800M is active, so driver support and availability will favor the newer part.

Choose the RX 7800M for almost any use case. Choose the RX 6600M only if you specifically need its DX9 edge or if power draw is a hard constraint. The benchmark data does not support any other conclusion.