AMD Radeon RX 6650 XT vs NVIDIA GeForce GTX 780 Comparison

# AMD Radeon RX 6650 XT vs NVIDIA GeForce GTX 780

The AMD Radeon RX 6650 XT and NVIDIA GeForce GTX 780 represent two very different eras of GPU design, separated by nearly a decade of architectural progress. The RX 6650 XT, built on RDNA 2.0 at 7 nm, enters the comparison as the modern contender, while the GTX 780, a 28 nm Kepler part from 2013, stands as the veteran. The head-to-head benchmark data shows the RX 6650 XT winning two of three tests, but the GTX 780 claims a surprising victory in one compute workload, making this a more nuanced matchup than raw generational advantage might suggest.

Head-to-Head Benchmarks

The most decisive result comes from Geekbench Metal, where the RX 6650 XT posts a score of 97,969 against the GTX 780's 10,114. That is a delta of 868.6% in favor of AMD, a staggering margin that reflects not just raw compute but also how modern APIs and driver optimizations leverage the newer architecture. In Geekbench Vulkan, the RX 6650 XT again dominates, scoring 81,306 versus 24,514 for the GTX 780, a 231.7% advantage. These two wins establish the RX 6650 XT as the clear leader in modern, low-level API workloads.

However, the Geekbench OpenCL result flips the script. The GTX 780 scores 22,863, while the RX 6650 XT manages only 10,111 — a 55.8% deficit for AMD. This is a significant outlier, suggesting that the GTX 780's Kepler architecture, with its 2,304 shading units and 192 texture mapping units, still excels in certain compute patterns that OpenCL exposes, particularly those that favor raw shader throughput over newer features like ray accelerators or mesh shaders. The RX 6650 XT's lower shading unit count (2,048) and narrower 128-bit memory bus may contribute to this underperformance in OpenCL, even though its 10.79 TFLOPS FP32 rating is more than double the GTX 780's 4.156 TFLOPS.

Looking at the average benchmark scores, the RX 6650 XT holds a narrow lead: 19,765 versus 19,164 for the GTX 780, a difference of roughly 3.1%. This slim margin is surprising given the generational gap, but it underscores how the GTX 780's high memory bandwidth (288.4 GB/s on a 384-bit bus) and substantial transistor count (7,080 million) keep it competitive in legacy workloads. The RX 6650 XT's percentile ranking of 65 against all GPUs edges out the GTX 780's 64, but both cards sit in similar territory — neither is a top-tier performer today.

FAQ

Q: Which card wins in Vulkan performance?

A: The AMD Radeon RX 6650 XT wins decisively, scoring 81,306 in Geekbench Vulkan versus 24,514 for the GTX 780, a 231.7% advantage. This reflects the RX 6650 XT's modern Vulkan 1.4 support and RDNA 2.0 architecture, which is better optimized for low-overhead APIs.

Q: Is the GTX 780 faster in any benchmark?

A: Yes, the GTX 780 beats the RX 6650 XT in Geekbench OpenCL, scoring 22,863 against 10,111, a 55.8% lead for NVIDIA. This is the only head-to-head test the GTX 780 wins, but it is a substantial one that suggests Kepler's compute capabilities remain relevant in specific OpenCL workloads.

Q: How do the average benchmark scores compare?

A: The RX 6650 XT has a higher average benchmark score of 19,765, while the GTX 780 averages 19,164. The difference is about 601 points, or roughly 3.1%, which is a narrow margin given the architectural gap between the two cards.

Q: What are the nearest rivals to each card?

A: The RX 6650 XT's nearest rival is the AMD FirePro W7000 with an average score of 19,905 (0.7% higher), followed by the NVIDIA Quadro K5200 at 19,602 (0.8% lower). The GTX 780's closest competitor is the NVIDIA TITAN Xp at 19,177 (0.1% higher), with the AMD Radeon RX 6600 at 19,036 (0.7% lower).

Q: Which card has better memory bandwidth?

A: The GTX 780 has slightly higher memory bandwidth at 288.4 GB/s, thanks to its 384-bit bus and 6 Gbps effective GDDR5 speed. The RX 6650 XT achieves 280.3 GB/s over a 128-bit bus with 17.5 Gbps effective GDDR6 speed, so the difference is minimal despite the very different bus widths.

Q: Do both cards support modern DirectX features?

A: No. The RX 6650 XT supports DirectX 12 Ultimate (12_2), which includes features like ray tracing and variable rate shading. The GTX 780 only supports DirectX 12 (11_0), which lacks these newer features, limiting its compatibility with the latest game titles.

Architecture Differences

The RX 6650 XT is built on RDNA 2.0 architecture using TSMC's 7 nm process node, packing 11,060 million transistors into a 237 mm² die. This gives it a transistor density of 46.7 million per mm², a figure that reflects the efficiency of modern manufacturing. The GTX 780, in contrast, uses the older Kepler architecture on a 28 nm node, with 7,080 million transistors spread across a much larger 561 mm² die, resulting in a density of just 12.6 million per mm². The smaller, denser design of the RX 6650 XT enables higher clock speeds — 2,055 MHz base and 2,635 MHz boost versus 863 MHz base and 902 MHz boost for the GTX 780 — which drives much of its performance advantage.

Memory architecture differs significantly. The RX 6650 XT uses 8 GB of GDDR6 on a 128-bit bus, achieving 280.3 GB/s bandwidth. The GTX 780 uses 3 GB of GDDR5 on a 384-bit bus, achieving 288.4 GB/s. The GDDR6 memory runs at 17.5 Gbps effective, while the GTX 780's GDDR5 runs at 6 Gbps effective, so the RX 6650 XT compensates for its narrower bus with much faster memory. The RX 6650 XT also includes 32 ray tracing cores, a feature entirely absent from the GTX 780, which has no RT cores or tensor cores. This makes the RX 6650 XT compatible with DirectX 12 Ultimate, while the GTX 780 is limited to DirectX 12 (11_0).

The RX 6650 XT supports PCIe 4.0 x8, while the GTX 780 uses PCIe 3.0 x16. Both cards have dual-slot cooling, but the GTX 780 is physically larger at 267 mm in length, 111 mm in height, and 38 mm in width, whereas the RX 6650 XT's dimensions are not specified in the data. Display outputs also differ: the RX 6650 XT offers 1x HDMI 2.1 and 3x DisplayPort 1.4a, while the GTX 780 provides 2x DVI, 1x HDMI 1.4a, and 1x DisplayPort 1.2.

Specification Differences

The two cards diverge on nearly every specification. The RX 6650 XT has 2,048 shading units, 128 TMUs, and 64 ROPs, while the GTX 780 has 2,304 shading units, 192 TMUs, and 48 ROPs. The GTX 780 has more shading units and TMUs, but the RX 6650 XT compensates with higher clock speeds, achieving a pixel rate of 168.6 GPixel/s and a texture rate of 337.3 GTexel/s, versus 43.30 GPixel/s and 173.2 GTexel/s for the GTX 780. FP32 compute is also heavily in favor of the RX 6650 XT at 10.79 TFLOPS, more than double the GTX 780's 4.156 TFLOPS.

Power requirements are notably different. The RX 6650 XT has a TDP of 176 W and requires a single 8-pin power connector with a suggested 450 W PSU. The GTX 780 has a 250 W TDP, needs both a 6-pin and 8-pin connector, and recommends a 600 W PSU. The RX 6650 XT is thus more power-efficient per watt of performance, a direct result of its 7 nm process. The GTX 780's launch MSRP was 649 USD, while the RX 6650 XT launched at 399 USD, though pricing is not a factor in performance analysis here.

The RX 6650 XT supports Vulkan 1.4, while the GTX 780 supports Vulkan 1.2.175. Both cards support OpenGL 4.6. The RX 6650 XT's DirectX 12 Ultimate (12_2) support is a significant advantage over the GTX 780's DirectX 12 (11_0), enabling features like ray tracing that the GTX 780 cannot use.

Where Each One Wins

The RX 6650 XT is the clear winner for modern gaming and graphics workloads. Its 231.7% lead in Vulkan and 868.6% lead in Metal demonstrates that it handles contemporary APIs with far greater efficiency. The 8 GB of GDDR6 memory, while on a narrower bus, provides more capacity for modern textures and higher resolutions. The DirectX 12 Ultimate support and ray tracing cores make it suitable for the latest game titles that require these features. For any GPU-accelerated task that uses Vulkan or Metal, the RX 6650 XT is the obvious choice.

The GTX 780 wins in OpenCL compute, with a 55.8% advantage over the RX 6650 XT. This makes it a viable option for legacy compute workloads that rely on OpenCL and do not benefit from modern API features. Its larger 384-bit memory bus and higher shading unit count appear to give it an edge in certain parallel compute patterns. The GTX 780 also has higher memory bandwidth (288.4 GB/s), which can be advantageous in memory-bound tasks. However, its 3 GB of VRAM is a limitation for large datasets or modern games.

In terms of average benchmark scores, the RX 6650 XT leads slightly, but the GTX 780's nearest rivals list includes the NVIDIA TITAN Xp and the AMD Radeon RX 6600, showing it remains competitive in its performance class. The RX 6650 XT's rivals include professional workstation cards like the Quadro K5200 and FirePro W7000, indicating it sits in a different performance tier despite similar average scores.

The Verdict

The data suggests that the RX 6650 XT is the better choice for anyone building a system for modern gaming or general-purpose GPU compute using Vulkan or Metal. Its massive wins in those benchmarks, combined with DirectX 12 Ultimate support, ray tracing cores, and 8 GB of VRAM, make it a far more future-proof option. The GTX 780's single OpenCL win is notable but narrow in scope; it indicates that Kepler's compute architecture still has strengths, but these are increasingly irrelevant as software shifts toward newer APIs.

For legacy OpenCL compute tasks, the GTX 780 holds a niche advantage, and its higher memory bandwidth and shading unit count may appeal to users running specific scientific or professional workloads that have not transitioned to modern APIs. However, its 3 GB VRAM, higher power draw (250 W TDP), and lack of modern features like ray tracing make it a poor investment for current gaming.

The RX 6650 XT's percentile rank of 65 versus the GTX 780's 64 is a near tie, but the RX 6650 XT's wins are in the tests that matter most for today's software ecosystem. The verdict is clear: choose the RX 6650 XT for general use, modern gaming, and future compatibility, and consider the GTX 780 only if you have a specific OpenCL workload where its 55.8% advantage directly applies. The data does not support the GTX 780 as a general-purpose alternative in 2024.