AMD Radeon RX 6600M vs NVIDIA GeForce GTX 780 Comparison

Head-to-Head Benchmarks

The recorded data shows a decisive overall advantage for the AMD Radeon RX 6600M across all three shared benchmark tests. The database lists three head-to-head comparisons, and the AMD part wins every one of them, with a final tally of 3 wins for AMD and 0 for the NVIDIA GeForce GTX 780.

The largest margin appears in the Geekbench Metal test. The RX 6600M scores 92,237 points, while the GTX 780 manages only 10,114 points. That is a delta of 812%, meaning the AMD mobile part delivers roughly nine times the Metal performance of the NVIDIA desktop card from the previous decade. This is the single most lopsided result in the comparison, and it reflects both the age gap and the architectural shift between the two products.

In the Geekbench Vulkan test, the RX 6600M records 73,740 points against 24,514 points for the GTX 780. The delta here is 200.8%, so the AMD part is about three times faster in Vulkan workloads. The GTX 780's Kepler architecture was never designed for modern explicit graphics APIs, and the data reflects that limitation clearly.

The Geekbench OpenCL test shows a similar pattern. The RX 6600M scores 67,765 points, while the GTX 780 scores 22,863 points. That is a 196.4% delta, again putting the AMD part at roughly three times the compute throughput of the NVIDIA card. OpenCL is a more mature compute interface than Vulkan or Metal, and while the gap narrows slightly compared to the Vulkan result, it remains enormous.

Looking at the broader database averages, the RX 6600M holds an average benchmark score of 23,273, which places it at the 68th percentile among all GPUs. The GTX 780, by contrast, has an average score of 19,164 and sits at the 64th percentile. The difference in average scores is roughly 21%, which is far smaller than the head-to-head deltas would suggest. This is because the Geekbench compute tests heavily favor the newer architecture, while the overall average includes many other workload types where the gap is less pronounced.

The nearest rivals listed for each card provide additional context. The RX 6600M's closest competitor is the AMD Radeon R9 M290X, with an average score of 23,276 and a delta of 0%. The NVIDIA P106-100 and AMD Radeon Pro Vega 16 are also within 0.1% of the RX 6600M's average. For the GTX 780, the nearest rival is the NVIDIA TITAN Xp at 19,177 points, a delta of 0.1%, followed by the Tesla K20m at 19,089 points. Interestingly, the AMD Radeon RX 6600, the desktop sibling of the mobile RX 6600M, sits only 0.7% behind the GTX 780 in average score, which underscores how much the GTX 780 benefits from its inclusion in a broad average across many test types.

Architecture Differences

The two GPUs come from fundamentally different eras and design philosophies. The AMD Radeon RX 6600M uses the Navi 23 chip built on RDNA 2.0 architecture, fabricated on a 7 nm process at TSMC. The NVIDIA GeForce GTX 780 uses the GK110 chip with Kepler architecture, fabricated on a 28 nm process, also at TSMC. The process node gap alone, 7 nm versus 28 nm, explains a large portion of the efficiency and density differences between the two.

Transistor counts tell a striking story. The RX 6600M packs 11,060 million transistors into a die size of 237 mm², giving a transistor density of 46.7 million transistors per square millimeter. The GTX 780 has 7,080 million transistors on a much larger die of 561 mm², yielding only 12.6 million transistors per square millimeter. The RX 6600M achieves nearly four times the transistor density of the GTX 780, which is a direct consequence of the newer manufacturing process.

The memory subsystems are also very different. The RX 6600M comes with 8 GB of GDDR6 memory on a 128-bit bus, delivering 224.0 GB/s of bandwidth. The GTX 780 has 3 GB of GDDR5 memory on a 384-bit bus, delivering 288.4 GB/s. Despite having a narrower bus, the RX 6600M's GDDR6 memory operates at 14 Gbps effective, compared to 6 Gbps effective for the GTX 780's GDDR5. The GTX 780 still holds a bandwidth advantage of about 29%, but the AMD card has more than double the capacity, which matters increasingly for modern workloads.

The compute units differ in configuration as well. The RX 6600M has 1,792 shading units, 112 texture mapping units, and 64 raster operation units. It also includes 28 ray tracing cores, a feature the GTX 780 lacks entirely. The GTX 780 has 2,304 shading units, 192 TMUs, and 48 ROPs. In raw shading unit count, the NVIDIA card has more, but the RX 6600M's RDNA 2 architecture executes instructions far more efficiently per unit. The FP32 compute figures confirm this: the RX 6600M delivers 8.659 TFLOPS against 4.156 TFLOPS for the GTX 780, more than double the floating-point throughput.

The GTX 780 has no FP16 support listed, while the RX 6600M can reach 17.32 TFLOPS in FP16 using a 2:1 ratio. The RX 6600M also supports DirectX 12 Ultimate (12_2), Vulkan 1.4, and OpenGL 4.6. The GTX 780 supports DirectX 12 (11_0), Vulkan 1.2.175, and OpenGL 4.6. The DirectX feature level difference is significant: 12_2 enables hardware ray tracing and mesh shaders, which the Kepler architecture cannot handle.

Power consumption is another major divider. The RX 6600M has a TDP of 100 W and uses no external power connectors, reflecting its mobile IGP form factor. The GTX 780 has a 250 W TDP, requires a 1x 6-pin plus 1x 8-pin power connector setup, and has a suggested PSU of 600 W. The RX 6600M draws less than half the power of the GTX 780 while delivering far higher benchmark scores. The GTX 780 is a dual-slot desktop card measuring 267 mm in length, 111 mm in height, and 38 mm in width. The RX 6600M is listed as IGP slot width, with display outputs described as portable device dependent.

Where Each One Wins

The RX 6600M wins in every shared benchmark category, but the magnitude of the wins varies by workload type. The strongest advantage appears in Metal, where the delta reaches 812%. This makes sense given that Metal is a modern low-level API designed for the current generation of GPUs, and the RX 6600M's RDNA 2 architecture was built with such APIs in mind. The GTX 780's Kepler architecture predates Metal's design assumptions by several years.

In Vulkan, the RX 6600M is 200.8% ahead. Vulkan is another explicit API that benefits from modern hardware features like asynchronous compute and better command buffer handling. The RX 6600M's architecture handles these workloads natively, while the GTX 780 relies on driver translation layers that add overhead.

OpenCL shows the smallest but still massive gap at 196.4%. Compute workloads in OpenCL often scale with raw FP32 throughput and memory bandwidth, and while the GTX 780 has more bandwidth, the RX 6600M's FP32 output of 8.659 TFLOPS versus 4.156 TFLOPS is the dominant factor. The RX 6600M's higher transistor density and newer process node also contribute to better compute efficiency per watt.

For real-world use cases, the database suggests that the RX 6600M is the clear choice for modern gaming at 1080p and 1440p, particularly in titles that use DirectX 12 Ultimate features like ray tracing. The GTX 780, despite its age, retains a niche in legacy applications where its 384-bit memory bus and 288.4 GB/s bandwidth can still be leveraged, particularly in older DirectX 11 titles. Its higher bandwidth relative to the RX 6600M could benefit certain bandwidth-bound workloads, though the RX 6600M's architectural efficiency generally compensates.

The GTX 780 also has a place in systems where PCIe 3.0 x16 is the only available interface, since the RX 6600M uses PCIe 4.0 x8. In practice, the bandwidth difference between PCIe 3.0 x16 and PCIe 4.0 x8 is minimal for most workloads, but the compatibility factor is worth noting for older platforms.

Specification Differences

The two cards differ in nearly every specification category. The process node is 7 nm for AMD versus 28 nm for NVIDIA. Transistor count is 11,060 million for AMD versus 7,080 million for NVIDIA. Die size is 237 mm² for AMD versus 561 mm² for NVIDIA. Transistor density is 46.7M per mm² for AMD versus 12.6M per mm² for NVIDIA.

Clock speeds show the RX 6600M running at a base of 2068 MHz and a boost of 2416 MHz, with a game clock of 2177 MHz. The GTX 780 runs at 863 MHz base and 902 MHz boost. Memory clocks are 1750 MHz (14 Gbps effective) for AMD versus 1502 MHz (6 Gbps effective) for NVIDIA. Memory size is 8 GB GDDR6 for AMD versus 3 GB GDDR5 for NVIDIA. Bus width is 128-bit for AMD versus 384-bit for NVIDIA. Bandwidth is 224.0 GB/s for AMD versus 288.4 GB/s for NVIDIA.

Shading units are 1,792 for AMD versus 2,304 for NVIDIA. TMUs are 112 for AMD versus 192 for NVIDIA. ROPs are 64 for AMD versus 48 for NVIDIA. The RX 6600M has 28 ray tracing cores; the GTX 780 has none. Pixel rate is 154.6 GPixel/s for AMD versus 43.30 GPixel/s for NVIDIA. Texture rate is 270.6 GTexel/s for AMD versus 173.2 GTexel/s for NVIDIA. FP32 is 8.659 TFLOPS for AMD versus 4.156 TFLOPS for NVIDIA. FP16 is 17.32 TFLOPS for AMD versus not listed for NVIDIA.

TDP is 100 W for AMD versus 250 W for NVIDIA. Slot width is IGP for AMD versus dual-slot for NVIDIA. Power connectors are none for AMD versus 1x 6-pin plus 1x 8-pin for NVIDIA. The GTX 780 has a suggested PSU of 600 W; the RX 6600M has none listed. Bus interface is PCIe 4.0 x8 for AMD versus PCIe 3.0 x16 for NVIDIA. Display outputs are portable device dependent for AMD versus 2x DVI, 1x HDMI 1.4a, and 1x DisplayPort 1.2 for NVIDIA. The GTX 780 has dimensions of 267 mm length, 111 mm height, and 38 mm width; the RX 6600M has no dimensions listed.

DirectX support is 12 Ultimate (12_2) for AMD versus 12 (11_0) for NVIDIA. Vulkan support is 1.4 for AMD versus 1.2.175 for NVIDIA. OpenGL is 4.6 for both. Release dates are May 2021 for AMD versus May 2013 for NVIDIA. The GTX 780 has a launch MSRP of 649 USD, while the RX 6600M has no launch MSRP listed.

FAQ

Q: Which GPU has the higher average benchmark score?

A: The AMD Radeon RX 6600M has an average benchmark score of 23,273, compared to 19,164 for the NVIDIA GeForce GTX 780. The RX 6600M also sits at the 68th percentile among all GPUs, while the GTX 780 sits at the 64th percentile.

Q: How large is the performance gap in the head-to-head Metal test?

A: In the Geekbench Metal test, the RX 6600M scores 92,237 points against 10,114 points for the GTX 780, a delta of 812% in favor of the AMD part.

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

A: Yes. The GTX 780 has a 384-bit memory bus and delivers 288.4 GB/s of bandwidth, while the RX 6600M has a 128-bit bus and delivers 224.0 GB/s. The GTX 780's bandwidth advantage is about 29%.

Q: What ray tracing capabilities does each GPU have?

A: The RX 6600M includes 28 ray tracing cores as part of its RDNA 2 architecture. The GTX 780 has no ray tracing cores listed, and its DirectX 12 (11_0) support does not include the ray tracing features found in DirectX 12 Ultimate.

Q: How do the power requirements compare?

A: The RX 6600M has a TDP of 100 W and requires no external power connectors. The GTX 780 has a TDP of 250 W, requires a 1x 6-pin plus 1x 8-pin power connector setup, and has a suggested PSU of 600 W.

Q: What is the release date difference between the two cards?

A: The RX 6600M was released on May 30, 2021, while the GTX 780 was released on May 22, 2013. Both are now listed as end-of-life products.