AMD Radeon RX 6600S vs NVIDIA GeForce GTX 780M Comparison

The AMD Radeon RX 6600S decisively outperforms the NVIDIA GeForce GTX 780M in the only shared benchmark, but the comparison is more nuanced than a single score suggests. The GTX 780M is a legacy Kepler part from 2013, while the RX 6600S is a modern RDNA 2.0 mobile chip from 2022, and the data reflects a generational leap in compute capability and API support. The RX 6600S wins the head-to-head contest 1-0, yet the GTX 780M holds a higher overall percentile ranking (50th vs. 49th) despite its age, indicating that raw compute throughput isn't the only factor in overall GPU hierarchy.

Head-to-Head Benchmarks

The sole direct benchmark comparison available is Geekbench OpenCL, and the results are lopsided. The AMD Radeon RX 6600S scores 66,435, while the NVIDIA GeForce GTX 780M trails far behind at 12,769. This represents a deltaPct of -80.8% for the NVIDIA part, meaning the RX 6600S delivers roughly 5.2 times the OpenCL compute performance. This is not a marginal victory; it is a complete rout. The RX 6600S's FP32 throughput of 7.168 TFLOPS versus the GTX 780M's 2.448 TFLOPS explains the gap, as does the newer architecture's higher clock speeds (2000 MHz boost vs. 797 MHz boost).

However, the GTX 780M is not without its own statistical claims. Its average benchmark score across all tests is 11,261, which is actually higher than the RX 6600S's average of 10,629. This counterintuitive result stems from the fact that the RX 6600S's average is dragged down by its poor Passmark DirectX scores (81 in DX10, 105 in DX11, 56 in DX12, 176 in DX9), while the GTX 780M's three Geekbench scores (8,319 Metal, 12,769 OpenCL, 12,696 Vulkan) are consistently in the five-figure range. The RX 6600S's Passmark G3D score of 12,649 is strong, but its DirectX legacy scores are anomalously low, pulling its average down.

In terms of nearest rivals, the GTX 780M sits just 0.3% above the AMD Radeon Pro WX 3200 and the AMD FirePro W4300, and 1.6% above both NVIDIA RTX PRO 6000 Blackwell Max-Q variants. The RX 6600S, by contrast, is 0.4% above the AMD Radeon R9 M275X, 1.4% above the AMD Radeon RX 550X, and actually 0.6% below the NVIDIA GeForce GTX 560 Ti and 1.2% below the NVIDIA Quadro K2200. This places the two cards in similar competitive tiers, despite the massive OpenCL delta.

The Verdict

The data is unambiguous: the AMD Radeon RX 6600S is the superior compute performer and the only rational choice for any workload that leverages OpenCL or modern graphics APIs. Its 66,435 OpenCL score is more than five times the GTX 780M's 12,769, and its FP32 throughput of 7.168 TFLOPS is nearly triple the older card's 2.448 TFLOPS. The RX 6600S also supports DirectX 12 Ultimate (12_2) and Vulkan 1.4, while the GTX 780M is limited to DirectX 12 (11_0) and Vulkan 1.2.175. For any modern gaming or compute task, the RX 6600S is the clear winner.

The GTX 780M's only statistical advantage is its higher percentile rank (50th vs. 49th) and a slightly higher average benchmark score (11,261 vs. 10,629). But these figures are misleading. The GTX 780M's average is based on only three Geekbench tests, none of which approach the RX 6600S's OpenCL result. The RX 6600S's average is dragged down by its Passmark DX scores, which are likely measuring legacy API paths that the modern RDNA 2.0 architecture handles differently. A builder should not mistake the GTX 780M's percentile edge for actual performance superiority.

The RX 6600S also wins decisively on efficiency. Its TDP of 80 W is significantly lower than the GTX 780M's 122 W, meaning it delivers roughly 2.9 times the FP32 performance per watt. The RX 6600S's 7 nm process node (vs. 28 nm) and higher transistor density (46.7M / mm² vs. 12.0M / mm²) make this possible. The GTX 780M's 3,540 million transistors on a 294 mm² die are ancient history compared to the RX 6600S's 11,060 million on 237 mm².

Where Each One Wins

AMD Radeon RX 6600S wins decisively in OpenCL compute, with its 66,435 score dwarfing the GTX 780M's 12,769. It also wins on memory bandwidth, delivering 224.0 GB/s via GDDR6 on a 128-bit bus, versus the GTX 780M's 160.0 GB/s via GDDR5 on a 256-bit bus. The RX 6600S's texture rate of 224.0 GTexel/s and pixel rate of 128.0 GPixel/s are both far ahead of the GTX 780M's 102.0 GTexel/s and 25.50 GPixel/s. It supports modern APIs (DirectX 12 Ultimate, Vulkan 1.4) and has 28 ray tracing cores, a feature the GTX 780M lacks entirely. Its FP16 throughput of 14.34 TFLOPS (2:1) is also a significant advantage for mixed-precision workloads.

NVIDIA GeForce GTX 780M wins on raw memory bus width (256-bit vs. 128-bit) and has more TMUs (128 vs. 112), but these advantages do not translate into performance wins in the data. Its higher transistor density is not a factor. The GTX 780M's only practical edge is its higher percentile rank (50th vs. 49th) and its slightly higher average benchmark score (11,261 vs. 10,629), which is an artifact of test selection. In real-world compute, the RX 6600S's nearest rivals include the GTX 560 Ti and Quadro K2200, while the GTX 780M's rivals are the Radeon Pro WX 3200 and RTX PRO 6000 Blackwell Max-Q — a clear indication that the RX 6600S is in a different performance class despite the similar percentiles.

FAQ

Q: Which GPU has a higher average benchmark score?

A: The NVIDIA GeForce GTX 780M has a higher average benchmark score of 11,261, compared to the AMD Radeon RX 6600S's 10,629. However, this is driven by the RX 6600S's low Passmark DirectX scores, not by overall compute superiority.

Q: How much faster is the RX 6600S in OpenCL?

A: The AMD Radeon RX 6600S scores 66,435 in Geekbench OpenCL, while the NVIDIA GeForce GTX 780M scores 12,769. This is a deltaPct of -80.8% for the GTX 780M, meaning the RX 6600S is approximately 5.2 times faster.

Q: What are the TDP differences between the two cards?

A: The AMD Radeon RX 6600S has a TDP of 80 W, while the NVIDIA GeForce GTX 780M has a TDP of 122 W. The RX 6600S delivers significantly higher compute performance at a lower power draw.

Q: Which GPU supports ray tracing?

A: Only the AMD Radeon RX 6600S supports ray tracing, with 28 RT cores. The NVIDIA GeForce GTX 780M has no RT cores, as it predates ray tracing hardware.

Q: What are the memory specifications for each card?

A: Both cards have 4 GB of memory, but the RX 6600S uses GDDR6 on a 128-bit bus with 224.0 GB/s bandwidth, while the GTX 780M uses GDDR5 on a 256-bit bus with 160.0 GB/s bandwidth. The RX 6600S has higher bandwidth despite a narrower bus.

Q: What DirectX versions do the two GPUs support?

A: The AMD Radeon RX 6600S supports DirectX 12 Ultimate (12_2), while the NVIDIA GeForce GTX 780M supports DirectX 12 (11_0). The RX 6600S also supports Vulkan 1.4, compared to the GTX 780M's Vulkan 1.2.175.

Architecture Differences

The two GPUs represent entirely different eras of GPU design. The NVIDIA GeForce GTX 780M uses the GK104 chip on the Kepler architecture, manufactured on a 28 nm process at TSMC. It packs 3,540 million transistors into a 294 mm² die, yielding a transistor density of 12.0M / mm². It has 1,536 shading units, 128 TMUs, and 32 ROPs. Its base clock is 771 MHz with a boost of 797 MHz. The architecture supports DirectX 12 (11_0), OpenGL 4.6, and Vulkan 1.2.175, but lacks any ray tracing or tensor cores.

The AMD Radeon RX 6600S uses the Navi 23 chip on the RDNA 2.0 architecture, also manufactured by TSMC but on a 7 nm process. It contains 11,060 million transistors on a 237 mm² die, achieving a transistor density of 46.7M / mm² — nearly four times that of the Kepler part. It has 1,792 shading units, 112 TMUs, 64 ROPs, and 28 RT cores. Its base clock is 1700 MHz, with a game clock of 1881 MHz and a boost of 2000 MHz. The architecture supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. The RX 6600S also supports FP16 compute at 14.34 TFLOPS (2:1 ratio), a feature the GTX 780M lacks entirely.

The process node advantage is the defining architectural difference. The 7 nm node allows the RX 6600S to nearly quadruple transistor density while reducing TDP from 122 W to 80 W. The RX 6600S's FP32 throughput of 7.168 TFLOPS is nearly triple the GTX 780M's 2.448 TFLOPS, and its FP16 capability adds a further dimension. The RX 6600S also has a modern memory subsystem with GDDR6, while the GTX 780M relies on GDDR5.

Specification Differences

The two cards differ on nearly every measurable specification. The RX 6600S uses a newer process node (7 nm vs. 28 nm), has more transistors (11,060 million vs. 3,540 million), and a smaller die (237 mm² vs. 294 mm²). Its transistor density is 46.7M / mm² versus 12.0M / mm². Clock speeds are dramatically different: the RX 6600S has a base clock of 1700 MHz and boost of 2000 MHz, while the GTX 780M runs at 771 MHz base and 797 MHz boost. The RX 6600S also has a game clock of 1881 MHz, which the GTX 780M lacks.

Memory configurations differ in type and bandwidth: the RX 6600S uses 4 GB of GDDR6 on a 128-bit bus with 224.0 GB/s bandwidth, while the GTX 780M uses 4 GB of GDDR5 on a 256-bit bus with 160.0 GB/s bandwidth. The RX 6600S has more shading units (1,792 vs. 1,536) and ROPs (64 vs. 32), but fewer TMUs (112 vs. 128). The RX 6600S has 28 RT cores; the GTX 780M has none. Pixel rate is 128.0 GPixel/s for the RX 6600S versus 25.50 GPixel/s for the GTX 780M, and texture rate is 224.0 GTexel/s versus 102.0 GTexel/s. FP32 is 7.168 TFLOPS versus 2.448 TFLOPS, and the RX 6600S adds FP16 at 14.34 TFLOPS.

TDP differs significantly: 80 W for the RX 6600S versus 122 W for the GTX 780M. The RX 6600S uses an IGP slot width and PCIe 4.0 x8 bus interface, while the GTX 780M uses an MXM Module slot width and MXM-B (3.0) bus interface. Neither card has power connectors, and both have portable-device-dependent display outputs. The RX 6600S supports DirectX 12 Ultimate (12_2) and Vulkan 1.4, while the GTX 780M supports DirectX 12 (11_0) and Vulkan 1.2.175. Both support OpenGL 4.6.