AMD Radeon RX 6650M XT vs NVIDIA CMP 40HX Comparison

The NVIDIA CMP 40HX and AMD Radeon RX 6650M XT represent two divergent philosophies in GPU design: one a dedicated mining card stripped of display outputs, the other a mobile RDNA 2 part aimed at high-performance laptops. The data shows a single head-to-head benchmark, Geekbench OpenCL, where the NVIDIA CMP 40HX decisively outperforms the AMD part by 21.4%. This gap is substantial, but the story of these two GPUs extends far beyond a single score, touching on architectural generations, memory subsystems, and power efficiency.

Head-to-Head Benchmarks

The only direct benchmark comparison available is Geekbench OpenCL, and the results are unambiguous. The NVIDIA CMP 40HX scores 93,395, while the AMD Radeon RX 6650M XT scores 76,904. This translates to a 21.4% advantage for the NVIDIA card, a margin that places it clearly ahead in raw compute workloads that leverage OpenCL. The CMP 40HX also holds a Geekbench Vulkan score of 77,879, though no comparable Vulkan result exists for the RX 6650M XT in the data, leaving OpenCL as the sole point of direct comparison.

Looking at the broader benchmark landscape, the CMP 40HX’s average score of 85,637 places it at the 93rd percentile of all GPUs. Its nearest rivals include the AMD Radeon PRO W7600 (average 87,108, delta -1.7%) and NVIDIA Quadro GP100 (average 87,445, delta -2.1%), meaning the CMP 40HX sits just below these workstation-class cards. It is notably ahead of the AMD Radeon PRO W6600 (average 81,995, delta +4.4%) and AMD Radeon Pro Vega 64X (average 80,959, delta +5.8%). For the RX 6650M XT, its average score of 76,904 puts it at the 91st percentile, with nearest rivals including the NVIDIA GeForce RTX 5090 D (average 77,712, delta -1%) and AMD Radeon RX 6850M XT (average 78,940, delta -2.6%). The RX 6650M XT trails these competitors by small margins, but its 21.4% deficit to the CMP 40HX is a much larger gap than any of its nearest-rival deltas.

It is notably the CMP 40HX’s win count stands at 1, with zero wins for the RX 6650M XT. This does not mean the AMD card is without merit — it means that in the single test where both were measured under identical conditions, the NVIDIA card came out ahead. The magnitude of that win, 21.4%, is significant enough to suggest a consistent performance advantage in compute-heavy tasks, not a marginal edge.

Architecture Differences

The two GPUs come from different architectural eras and design intents. The NVIDIA CMP 40HX is built on the Turing architecture, fabricated on a 12 nm process at TSMC. It uses the TU106 chip, which contains 10,800 million transistors on a 445 mm² die, yielding a transistor density of 24.3M per mm². In contrast, the AMD Radeon RX 6650M XT uses the RDNA 2.0 architecture on a 7 nm process, also at TSMC. Its Navi 23 chip packs 11,060 million transistors into a much smaller 237 mm² die, achieving a density of 46.7M per mm². The AMD part is more than twice as dense per square millimeter, reflecting the newer process node.

Clock speeds tell a similar story of generational advancement. The CMP 40HX has a base clock of 1470 MHz and a boost clock of 1650 MHz. The RX 6650M XT starts at 2068 MHz base, boosts to 2416 MHz, and has a game clock of 2162 MHz. Even accounting for the older architecture, the AMD card’s higher clocks are a direct result of the 7 nm process. In terms of compute units, the CMP 40HX fields 2304 shading units, 144 TMUs, and 64 ROPs, along with 36 RT cores and 288 tensor cores. The RX 6650M XT has 2048 shading units, 128 TMUs, 64 ROPs, and 32 RT cores, but no tensor cores. The NVIDIA card thus has more shading units and RT cores, plus the tensor core advantage, which the AMD part lacks entirely.

Memory configurations are another major divergence. Both cards have 8 GB of GDDR6 memory, but the CMP 40HX uses a 256-bit bus, yielding a bandwidth of 448.0 GB/s at 14 Gbps effective memory speed. The RX 6650M XT uses a 128-bit bus, providing only 256.0 GB/s at 16 Gbps effective. Despite the AMD card’s faster memory clock, its narrower bus halves its bandwidth relative to the NVIDIA card. This is a critical difference for compute workloads that are memory-bandwidth sensitive.

Pixel and texture rates further illustrate the gap. The CMP 40HX delivers 105.6 GPixel/s and 237.6 GTexel/s, while the RX 6650M XT delivers 154.6 GPixel/s and 309.2 GTexel/s. The AMD part is faster in these rasterization-focused metrics due to its higher clocks. However, in raw FP32 throughput, the RX 6650M XT achieves 9.896 TFLOPS, ahead of the CMP 40HX’s 7.603 TFLOPS. The AMD card also leads in FP16 with 19.79 TFLOPS versus 15.21 TFLOPS for the NVIDIA card, both at 2:1 ratios. This suggests that while the CMP 40HX wins the OpenCL benchmark, the RX 6650M XT has higher theoretical compute peak.

Power and physical design are starkly different. The CMP 40HX has a TDP of 185 W, requires a single 8-pin power connector, and a suggested 450 W PSU. It is a dual-slot card measuring 229 mm in length, 111 mm in height, and 35 mm in width, with no display outputs. The RX 6650M XT, being a mobile part, has a TDP of just 120 W, uses no power connectors, and is listed as an IGP (integrated GPU) with portable-device-dependent outputs. Its dimensions are not specified, as it is designed to be soldered into laptops. The CMP 40HX uses a PCIe 1.0 x4 interface, while the RX 6650M XT uses PCIe 4.0 x8, giving the AMD part a more modern and faster bus connection.

Both cards support DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4, so API-level feature parity exists. The CMP 40HX was released on 2021-02-24, while the RX 6650M XT came later on 2022-01-03. Both are end-of-life products, with the RX 6650M XT’s predecessor listed as Polaris Mobile.

The Verdict

From the data, the NVIDIA CMP 40HX is the clear winner in the only benchmark where both were tested, leading the RX 6650M XT by 21.4% in Geekbench OpenCL. Its average score of 85,637 versus 76,904 for the AMD part reinforces this, as does its higher percentile ranking (93rd versus 91st). The CMP 40HX also offers substantially more memory bandwidth (448.0 GB/s versus 256.0 GB/s) and a wider 256-bit bus, which are decisive for many compute tasks. It also carries 288 tensor cores, which the RX 6650M XT does not have at all, making it the more capable option for any workload that can leverage those units.

However, the RX 6650M XT is not without its own advantages. It has a higher FP32 throughput (9.896 TFLOPS versus 7.603 TFLOPS) and higher pixel and texture rates (154.6 GPixel/s and 309.2 GTexel/s versus 105.6 GPixel/s and 237.6 GTexel/s). Its 7 nm process gives it better transistor density and much lower power consumption (120 W versus 185 W), and its PCIe 4.0 x8 interface is more modern than the CMP 40HX’s PCIe 1.0 x4. The RX 6650M XT also launched nearly a year later, benefiting from architectural refinements.

The verdict depends on the use case. For pure compute performance in a desktop or mining configuration, the CMP 40HX is the stronger choice based on benchmark data. For a mobile, power-efficient solution with higher theoretical compute rates, the RX 6650M XT is the only viable option, given the CMP 40HX has no display outputs and is not designed for portable systems. The CMP 40HX’s launch MSRP was 699 USD, a figure that reflects its professional mining orientation.

FAQ

Q: Which GPU has higher memory bandwidth?

A: The NVIDIA CMP 40HX has a bandwidth of 448.0 GB/s, while the AMD Radeon RX 6650M XT has 256.0 GB/s. The CMP 40HX’s 256-bit bus is double the width of the RX 6650M XT’s 128-bit bus.

Q: Does the AMD Radeon RX 6650M XT have tensor cores?

A: No. The RX 6650M XT has 32 RT cores but no tensor cores. The NVIDIA CMP 40HX has 288 tensor cores in addition to its 36 RT cores.

Q: What is the power consumption difference?

A: The NVIDIA CMP 40HX has a TDP of 185 W and requires a 1x 8-pin power connector with a suggested 450 W PSU. The AMD Radeon RX 6650M XT has a TDP of 120 W and uses no power connectors, as it is an IGP for mobile devices.

Q: Which card has a higher FP32 compute rate?

A: The AMD Radeon RX 6650M XT achieves 9.896 TFLOPS FP32, which is higher than the NVIDIA CMP 40HX’s 7.603 TFLOPS.

Q: How do their benchmark scores compare?

A: In Geekbench OpenCL, the NVIDIA CMP 40HX scores 93,395 versus 76,904 for the AMD Radeon RX 6650M XT, a 21.4% advantage for the NVIDIA card.

Q: Which GPU has a smaller die size?

A: The AMD Radeon RX 6650M XT has a die size of 237 mm², compared to 445 mm² for the NVIDIA CMP 40HX. The AMD part uses a 7 nm process, while the NVIDIA card uses 12 nm.

Where Each One Wins

The NVIDIA CMP 40HX wins in raw benchmark performance, as evidenced by its 21.4% lead in Geekbench OpenCL. Its 448.0 GB/s memory bandwidth and 256-bit bus make it better suited for memory-heavy compute tasks. The presence of 288 tensor cores gives it an edge in AI or ML workloads that can use them. Its dual-slot design, 185 W TDP, and 1x 8-pin connector make it a desktop-oriented card, and its 93rd percentile ranking places it among the top GPUs in the database. It also has a Geekbench Vulkan score of 77,879, which is not matched by the RX 6650M XT in the data.

The AMD Radeon RX 6650M XT wins in efficiency and portability. Its 120 W TDP is 65 W lower than the CMP 40HX, and its IGP form factor means it can be integrated into laptops. Its higher clocks (2416 MHz boost versus 1650 MHz) and higher FP32 throughput (9.896 TFLOPS versus 7.603 TFLOPS) suggest it would perform better in compute workloads that are clock-bound rather than bandwidth-bound. Its 7 nm process and higher transistor density (46.7M per mm² versus 24.3M per mm²) make it a more modern design. The RX 6650M XT also has a higher pixel rate (154.6 GPixel/s versus 105.6 GPixel/s) and texture rate (309.2 GTexel/s versus 237.6 GTexel/s), making it potentially faster in rasterization-focused scenarios. Its PCIe 4.0 x8 interface, while narrower than full x16, is a generation ahead of the CMP 40HX’s PCIe 1.0 x4.

In summary, the CMP 40HX is the benchmark winner for raw compute, while the RX 6650M XT wins on power efficiency and theoretical peak performance. The choice between them hinges on whether the user prioritizes tested benchmark results or architectural modernity and mobile compatibility.