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

The GeForce GTX 780 Ti and the Radeon RX 6600M represent two distinct eras of GPU design, separated by nearly eight years of architectural evolution. The data shows a decisive performance shift: the AMD Radeon RX 6600M wins all three head-to-head benchmarks, with its smallest margin being a 59.7% lead over the NVIDIA card in Geekbench OpenCL. This analysis breaks down where each card excels, the architectural reasons behind the gap, and what the numbers mean for different workloads.

Where Each One Wins

The performance split is stark, with the Radeon RX 6600M dominating every measured category. The GeForce GTX 780 Ti records zero benchmark wins against the RX 6600M, while the AMD card wins all three head-to-head tests. The closest contest is in Geekbench OpenCL, where the RX 6600M scores 67,765 against the GTX 780 Ti's 27,326—a 59.7% advantage. The gap widens further in Geekbench Vulkan, where the RX 6600M's 73,740 surpasses the GTX 780 Ti's 27,238 by 63.1%. The most lopsided result appears in Geekbench Metal, where the RX 6600M's 92,237 dwarfs the GTX 780 Ti's 18,144 by 80.3%.

The GTX 780 Ti's strongest showing relative to its rival is in OpenCL, though it still loses decisively. The AMD card's advantage stems from its modern RDNA 2.0 architecture, which delivers higher raw compute throughput and better API support. For compute-heavy workloads like OpenCL, the RX 6600M's 8.659 TFLOPS of FP32 performance versus the GTX 780 Ti's 5.345 TFLOPS provides a fundamental edge. The RX 6600M also leads in texture rate, posting 270.6 GTexel/s against the older card's 222.7 GTexel/s, and in pixel rate, with 154.6 GPixel/s versus 55.68 GPixel/s.

Architecture Differences

The architectural gap between these two GPUs is generational. The GTX 780 Ti uses the GK110B chip on a 28 nm TSMC process, packing 7,080 million transistors into a 561 mm² die. The RX 6600M employs the Navi 23 chip on a 7 nm TSMC process, fitting 11,060 million transistors into just 237 mm². This process shrink explains the transistor density difference: the RX 6600M achieves 46.7M transistors per square millimeter, nearly four times the GTX 780 Ti's 12.6M / mm².

The core configurations diverge significantly. The GTX 780 Ti has 2,880 shading units, 240 texture mapping units, and 48 ROPs. The RX 6600M has fewer shading units at 1,792, fewer TMUs at 112, but more ROPs at 64. The AMD card also includes 28 ray tracing cores, a feature entirely absent from the Kepler-based GTX 780 Ti. Memory subsystems differ sharply: the GTX 780 Ti uses 3 GB of GDDR5 on a 384-bit bus for 336.6 GB/s bandwidth, while the RX 6600M uses 8 GB of GDDR6 on a 128-bit bus for 224.0 GB/s. Despite the narrower bus, the RX 6600M's faster 14 Gbps effective memory clock compensates partially, though the GTX 780 Ti retains a bandwidth advantage.

Clock speeds show the generational leap. The RX 6600M runs at a 2068 MHz base and 2416 MHz boost, with a 2177 MHz game clock. The GTX 780 Ti's base is 875 MHz with a 928 MHz boost. Power draw tells a different story: the GTX 780 Ti consumes 250 W TDP with dual-slot cooling and 1x 6-pin + 1x 8-pin connectors, while the RX 6600M is an IGP-class chip at 100 W TDP with no power connectors. The RX 6600M also supports PCIe 4.0 x8, while the GTX 780 Ti uses PCIe 3.0 x16.

Head-to-Head Benchmarks

The benchmark data paints a clear picture of the RX 6600M's superiority. In Geekbench Metal, the RX 6600M scores 92,237 versus the GTX 780 Ti's 18,144—an 80.3% delta that represents the largest single gap. This result reflects the AMD card's modern architecture and its ability to leverage Metal's compute capabilities more effectively. The GTX 780 Ti, released in 2013, predates Metal's widespread adoption and lacks the hardware features needed to compete.

Geekbench Vulkan shows a 63.1% advantage for the RX 6600M, with scores of 73,740 against 27,238. Vulkan support is where the architectural differences become apparent: the GTX 780 Ti supports Vulkan 1.2.175, while the RX 6600M supports Vulkan 1.4. The newer API version, combined with RDNA 2.0's improved command processor efficiency, explains the substantial gap. The RX 6600M's higher FP32 throughput of 8.659 TFLOPS versus 5.345 TFLOPS also contributes to Vulkan's compute-friendly workload.

Geekbench OpenCL produces the closest result, but the RX 6600M still wins by 59.7%, scoring 67,765 against 27,326. The GTX 780 Ti's 384-bit memory bus provides 336.6 GB/s of bandwidth, which helps in memory-bound OpenCL kernels, but the RX 6600M's superior compute density and higher clocks overcome this advantage. The RX 6600M's texture rate of 270.6 GTexel/s versus 222.7 GTexel/s for the GTX 780 Ti also matters in graphics-heavy OpenCL tests. Across all three benchmarks, the RX 6600M's average score is 23,273, while the GTX 780 Ti averages 24,236—a difference that appears counterintuitive given the head-to-head results but reflects the different benchmark suites each card was tested with.

FAQ

Q: Which card has better raw compute performance?

A: The RX 6600M delivers 8.659 TFLOPS of FP32 performance, which is 62% higher than the GTX 780 Ti's 5.345 TFLOPS. This compute advantage directly translates to its wins in Geekbench OpenCL and Vulkan tests.

Q: Does the GTX 780 Ti have any memory bandwidth advantage?

A: Yes, the GTX 780 Ti offers 336.6 GB/s of bandwidth from its 384-bit GDDR5 interface, compared to the RX 6600M's 224.0 GB/s from a 128-bit GDDR6 bus. However, this does not translate to benchmark wins, as the RX 6600M's higher clocks and compute efficiency overcome the bandwidth deficit.

Q: What is the transistor density difference between these two GPUs?

A: The RX 6600M has a transistor density of 46.7M / mm², which is 3.7 times higher than the GTX 780 Ti's 12.6M / mm². This reflects the 7 nm process advantage over the older 28 nm node.

Q: Which card supports ray tracing?

A: Only the RX 6600M includes 28 ray tracing cores. The GTX 780 Ti, based on Kepler architecture, has no ray tracing hardware and supports DirectX 12 (11_1) compared to the RX 6600M's DirectX 12 Ultimate (12_2).

Q: How do their power requirements compare?

A: The GTX 780 Ti has a 250 W TDP and requires a 600 W suggested PSU with dual power connectors. The RX 6600M is an IGP-class chip with a 100 W TDP and no power connectors, making it suitable for laptop integration.

Q: What are the average benchmark scores for each card?

A: The GTX 780 Ti averages 24,236 across its tested benchmarks, placing it in the 70th percentile of all GPUs. The RX 6600M averages 23,273, placing it in the 68th percentile. These averages use different benchmark suites, so the head-to-head results are more indicative of relative performance.

Specification Differences

The two cards differ across nearly every measurable specification:

• Process Node: GTX 780 Ti uses 28 nm; RX 6600M uses 7 nm.
• Transistors: GTX 780 Ti has 7,080 million; RX 6600M has 11,060 million.
• Die Size: GTX 780 Ti measures 561 mm²; RX 6600M measures 237 mm².
• Transistor Density: GTX 780 Ti achieves 12.6M / mm²; RX 6600M achieves 46.7M / mm².
• Base Clock: GTX 780 Ti runs at 875 MHz; RX 6600M at 2068 MHz.
• Boost Clock: GTX 780 Ti boosts to 928 MHz; RX 6600M to 2416 MHz.
• Memory Size: GTX 780 Ti has 3 GB; RX 6600M has 8 GB.
• Memory Type: GTX 780 Ti uses GDDR5; RX 6600M uses GDDR6.
• Memory Bus: GTX 780 Ti uses 384-bit; RX 6600M uses 128-bit.
• Memory Bandwidth: GTX 780 Ti delivers 336.6 GB/s; RX 6600M delivers 224.0 GB/s.
• Shading Units: GTX 780 Ti has 2,880; RX 6600M has 1,792.
• TMUs: GTX 780 Ti has 240; RX 6600M has 112.
• ROPs: GTX 780 Ti has 48; RX 6600M has 64.
• Ray Tracing Cores: GTX 780 Ti has none; RX 6600M has 28.
• Pixel Rate: GTX 780 Ti achieves 55.68 GPixel/s; RX 6600M achieves 154.6 GPixel/s.
• Texture Rate: GTX 780 Ti achieves 222.7 GTexel/s; RX 6600M achieves 270.6 GTexel/s.
• FP32 Performance: GTX 780 Ti delivers 5.345 TFLOPS; RX 6600M delivers 8.659 TFLOPS.
• TDP: GTX 780 Ti consumes 250 W; RX 6600M consumes 100 W.
• Bus Interface: GTX 780 Ti uses PCIe 3.0 x16; RX 6600M uses PCIe 4.0 x8.
• DirectX Support: GTX 780 Ti supports DirectX 12 (11_1); RX 6600M supports DirectX 12 Ultimate (12_2).
• Vulkan Support: GTX 780 Ti supports Vulkan 1.2.175; RX 6600M supports Vulkan 1.4.
• Form Factor: GTX 780 Ti is dual-slot with power connectors; RX 6600M is IGP with no connectors.

The Verdict

The data is unambiguous: the Radeon RX 6600M outperforms the GeForce GTX 780 Ti in every head-to-head benchmark. For users prioritizing modern compute workloads, DirectX 12 Ultimate features, or ray tracing, the RX 6600M is the only choice—it offers 28 ray tracing cores, 8 GB of GDDR6 memory, and 8.659 TFLOPS of FP32 compute. Its 100 W TDP makes it suitable for portable devices, while the GTX 780 Ti's 250 W TDP and dual-slot design limit it to desktop builds with substantial power supplies.

The GTX 780 Ti retains niche advantages in memory bandwidth (336.6 GB/s versus 224.0 GB/s) and shading unit count (2,880 versus 1,792), but these do not translate to benchmark wins. Its 70th percentile ranking versus the RX 6600M's 68th percentile reflects different test suites rather than competitive performance. For anyone considering these two cards, the RX 6600M's 59.7% to 80.3% leads across OpenCL, Vulkan, and Metal benchmarks make it the clear recommendation. The GTX 780 Ti's end-of-life status, 2013 release, and lack of modern API support further cement the RX 6600M as the better choice for contemporary workloads.