AMD Radeon RX 6650M XT vs NVIDIA GeForce RTX 4090 Comparison

Head-to-Head Benchmarks

The database contains a single direct head-to-head benchmark between these two GPUs, and the result is decisive. In the Geekbench OpenCL test, the NVIDIA GeForce RTX 4090 scores 255,416, while the AMD Radeon RX 6650M XT scores 76,904. That represents a 69.9% deficit for the AMD part, meaning the NVIDIA GPU delivers more than three times the raw compute throughput in this OpenCL workload. The delta is stark: the RTX 4090 does not merely edge out the RX 6650M XT, it overwhelms it in absolute terms.

Looking at the broader database context, the RX 6650M XT sits at the 91st percentile among all GPUs, with an average benchmark score of 76,904. Its nearest rivals in the database are the NVIDIA GeForce RTX 5090 D at 77,712 (1% higher), the AMD Radeon RX 6850M XT at 78,940 (2.6% higher), and two Tesla P100 variants at 79,396 and 79,605 (3.1% and 3.4% higher respectively). This places the RX 6650M XT in a competitive tier for mobile GPUs, but that tier is far below the absolute performance ceiling.

The RTX 4090, by contrast, has an average benchmark score of 60,347 across all recorded tests, though its percentile rank is 88, slightly lower than the AMD part. This apparent contradiction is explained by the test mix: the RTX 4090's Geekbench OpenCL score is 255,416, but its average is dragged down by other workloads. The database shows additional scores for the RTX 4090: Passmark GPU Compute at 26,613, Passmark G3D at 38,194, Passmark G2D at 1,299, and a series of DirectX scores (10, 11, 12, 9) ranging from 150 to 397. The average of all these disparate tests, including the low DirectX scores, yields the 60,347 figure. The nearest rivals to the RTX 4090 by average score are the Intel Arc Pro A60 at 60,326 (0% delta), the AMD Radeon Pro Vega 48 at 60,140 (0.3% lower), the AMD Radeon Pro W6600M at 61,896 (2.5% higher), and the AMD Radeon PRO V710 at 58,657 (2.9% lower). This clustering around 60,000 suggests the RTX 4090's average is not representative of its peak capability, whereas the RX 6650M XT has only a single recorded benchmark, so its average equals its Geekbench score.

In the head-to-head OpenCL test, the RTX 4090 wins outright, and the database records one win for NVIDIA and zero for AMD. No other comparative benchmarks exist in the pack, so the narrative is built on this single data point, supported by the specification disparity.

The Verdict

The data is unambiguous: for raw compute performance in OpenCL, the NVIDIA GeForce RTX 4090 is the dominant choice. Its score of 255,416 versus 76,904 means a user seeking maximum throughput for compute-heavy tasks should select the RTX 4090 without hesitation. The 69.9% lead is not a marginal improvement; it is a generational gap.

However, the RX 6650M XT occupies a different segment entirely. It is an integrated graphics solution (IGP slot width) with a 120 W TDP, while the RTX 4090 is a triple-slot add-in board with a 450 W TDP and an 850 W suggested PSU. The RX 6650M XT is designed for mobile or compact systems where power and space are constrained. Its 91st percentile ranking among all GPUs is impressive for a part that draws only 120 W, whereas the RTX 4090's 88th percentile reflects its mixed benchmark results, not its peak performance.

For a laptop or small-form-factor build where the GPU must be integrated into the motherboard, the RX 6650M XT is the only viable choice between these two, given the RTX 4090's physical dimensions (304 mm length, 137 mm height, 61 mm width) and power connector requirements (1x 16-pin). For a desktop workstation or enthusiast rig with adequate cooling and power delivery, the RTX 4090 is the clear winner on every measurable performance metric in this comparison.

The database does not record a launch MSRP for the RX 6650M XT, but the RTX 4090 has a launch MSRP of 1,599 USD. The verdict, strictly from the data, is that the RTX 4090 is for users who prioritize compute performance above all else, while the RX 6650M XT is for those who need a capable GPU in a low-power, integrated form factor.

Architecture Differences

The two GPUs come from fundamentally different architectural lineages. The AMD Radeon RX 6650M XT is built on RDNA 2.0, using the Navi 23 chip, and belongs to the Radeon RX 6000 series. It is fabricated on a 7 nm process at TSMC, with 11,060 million transistors packed into a 237 mm² die, yielding a transistor density of 46.7 million transistors per square millimeter. The NVIDIA GeForce RTX 4090 uses the Ada Lovelace architecture, based on the AD102 chip, and is part of the GeForce 40 series. It is built on a 5 nm process at the same foundry, TSMC, but with 76,300 million transistors on a 609 mm² die, giving a density of 125.3 million transistors per square millimeter. The RTX 4090's die is more than 2.5 times larger and houses nearly seven times as many transistors, with a density that is over 2.6 times higher.

The shader configurations differ dramatically. The RX 6650M XT has 2,048 shading units, 128 texture mapping units, and 64 raster output units, plus 32 ray tracing cores. The RTX 4090 has 16,384 shading units, 512 TMUs, 176 ROPs, and 128 ray tracing cores. The RTX 4090 also includes 512 tensor cores, a feature entirely absent from the RX 6650M XT. This means the NVIDIA part is equipped for AI and deep learning workloads, while the AMD part has no such dedicated hardware.

In terms of compute rates, the RTX 4090 achieves 82.58 TFLOPS for both FP32 and FP16 (at a 1:1 ratio), whereas the RX 6650M XT delivers 9.896 TFLOPS for FP32 and 19.79 TFLOPS for FP16 (at a 2:1 ratio). The pixel rate is 443.5 GPixel/s for the RTX 4090 versus 154.6 GPixel/s for the AMD part, and the texture rate is 1,290.2 GTexel/s versus 309.2 GTexel/s. The RTX 4090's FP32 throughput is more than eight times higher, and its pixel rate is nearly three times higher.

The API support is identical: both support DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. The production status for both is end-of-life, but the release dates differ: the RX 6650M XT launched in January 2022, while the RTX 4090 launched in September 2022. The AMD part's predecessor is Polaris Mobile, and the RTX 4090's predecessor is GeForce 30, with a successor in GeForce 50.

Specification Differences

The memory subsystem is a major differentiator. The RX 6650M XT has 8 GB of GDDR6 memory on a 128-bit bus, with a bandwidth of 256.0 GB/s and a memory clock of 2000 MHz (16 Gbps effective). The RTX 4090 has 24 GB of GDDR6X memory on a 384-bit bus, with a bandwidth of 1.01 TB/s and a memory clock of 1313 MHz (21 Gbps effective). The NVIDIA part offers three times the capacity and roughly four times the bandwidth.

Clock speeds also differ. The RX 6650M XT has a base clock of 2068 MHz, a boost clock of 2416 MHz, and a game clock of 2162 MHz. The RTX 4090 has a base clock of 2235 MHz and a boost clock of 2520 MHz, with no game clock recorded. The RTX 4090 runs at higher clocks across the board.

Power and physical specifications are where the gap is most pronounced. The RX 6650M XT has a TDP of 120 W, a slot width of IGP (integrated), and no power connectors. The RTX 4090 has a TDP of 450 W, a triple-slot width, a single 16-pin power connector, and a suggested PSU of 850 W. The RTX 4090's physical dimensions are 304 mm in length, 137 mm in height, and 61 mm in width, while the RX 6650M XT has no recorded dimensions, consistent with its integrated nature.

The bus interface differs: the RX 6650M XT uses PCIe 4.0 x8, while the RTX 4090 uses PCIe 4.0 x16. Display outputs are portable-device-dependent for the AMD part, while the RTX 4090 offers 1x HDMI 2.1 and 3x DisplayPort 1.4a. The RTX 4090 also has a launch MSRP of 1,599 USD, while no MSRP is recorded for the RX 6650M XT.

FAQ

Q: Which GPU has a higher Geekbench OpenCL score?

A: The NVIDIA GeForce RTX 4090 scores 255,416, which is 69.9% higher than the AMD Radeon RX 6650M XT's 76,904.

Q: What is the memory capacity difference?

A: The RTX 4090 has 24 GB of GDDR6X memory, while the RX 6650M XT has 8 GB of GDDR6. The RTX 4090 also has a 384-bit bus versus 128-bit, and bandwidth of 1.01 TB/s versus 256.0 GB/s.

Q: How do their power requirements compare?

A: The RX 6650M XT has a TDP of 120 W and no power connectors, while the RTX 4090 has a TDP of 450 W, requires a 1x 16-pin connector, and recommends an 850 W PSU.

Q: Do both GPUs support the same APIs?

A: Yes, both support DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4.

Q: What is the transistor count on each chip?

A: The RX 6650M XT has 11,060 million transistors on a 237 mm² die, while the RTX 4090 has 76,300 million transistors on a 609 mm² die.

Q: Which GPU has ray tracing cores?

A: Both have ray tracing cores: the RX 6650M XT has 32, and the RTX 4090 has 128. The RTX 4090 also has 512 tensor cores, which the RX 6650M XT lacks.