AMD Radeon RX 6650M XT vs NVIDIA RTX 4000 SFF Ada Generation Comparison

Where Each One Wins

The benchmark data separates these two GPUs into distinct performance tiers. The NVIDIA RTX 4000 SFF Ada Generation wins the only recorded head-to-head benchmark, the Geekbench OpenCL test, with a score of 124,812 against the AMD Radeon RX 6650M XT's 76,904. That is a 62.3% advantage for the NVIDIA part. The Radeon RX 6650M XT has no wins in the recorded comparisons.

The NVIDIA card sits in the 95th percentile of all GPUs in the database, while the AMD part lands in the 91st percentile. This places both in the upper echelon of performance, but the delta between them is substantial. The RTX 4000 SFF's average benchmark score of 117,088 is roughly 52% higher than the Radeon's 76,904 average. For workloads that leverage OpenCL compute, the NVIDIA solution is the clear choice.

The AMD Radeon RX 6650M XT is a mobile part, and its performance profile reflects that positioning. It is an end-of-life product, while the NVIDIA card remains active in production. The use-case split favors the RTX 4000 SFF for raw compute throughput and for workstation duties, given its dual-slot form factor and display outputs. The Radeon, with its integrated graphics processor (IGP) slot width and portable-device-dependent outputs, targets laptop and mobile implementations where the NVIDIA card's physical design would not apply.

Architecture Differences

The two GPUs come from different architectural generations and design philosophies. The NVIDIA RTX 4000 SFF Ada Generation uses the AD104 chip built on Ada Lovelace architecture, manufactured on a 5 nm process at TSMC. It packs 35,800 million transistors into a 294 mm² die, yielding a transistor density of 121.8 million per mm². The AMD Radeon RX 6650M XT uses the Navi 23 chip on RDNA 2.0 architecture, also from TSMC but on a 7 nm process. That chip contains 11,060 million transistors on a 237 mm² die, for a density of 46.7 million per mm².

The NVIDIA chip has roughly 3.2 times the transistor count of the AMD chip, and more than 2.6 times the transistor density. This reflects the Ada Lovelace design's inclusion of dedicated hardware, including 48 RT cores and 192 tensor cores. The AMD part has 32 RT cores and no tensor cores listed. The NVIDIA card also has 6,144 shading units, 192 texture mapping units, and 64 ROPs. The AMD card has 2,048 shading units, 128 TMUs, and 64 ROPs. The NVIDIA GPU carries 3 times the shading units and 1.5 times the TMUs, while ROP counts match.

The NVIDIA card's clock behavior is notable: a base clock of 720 MHz and a boost clock of 1,560 MHz. The AMD part runs much higher, with a base of 2,068 MHz, a game clock of 2,162 MHz, and a boost of 2,416 MHz. Despite the higher clocks on the AMD side, the NVIDIA part achieves a higher FP32 throughput of 19.17 TFLOPS versus the AMD's 9.896 TFLOPS. The NVIDIA card also delivers a higher pixel rate of 99.84 GPixel/s and a texture rate of 299.5 GTexel/s. The AMD card posts a higher pixel rate of 154.6 GPixel/s and a texture rate of 309.2 GTexel/s, but its FP32 figure is roughly half.

Memory configurations differ significantly. The NVIDIA card has 20 GB of GDDR6 on a 160-bit bus, yielding 280.0 GB/s of bandwidth. The AMD card has 8 GB of GDDR6 on a 128-bit bus, for 256.0 GB/s. The NVIDIA memory runs at 1750 MHz with 14 Gbps effective, while the AMD memory runs at 2000 MHz with 16 Gbps effective. The NVIDIA card's larger memory pool is a clear advantage for workstation workloads with large datasets.

FAQ

Q: Which GPU has the higher FP32 compute throughput?

A: The NVIDIA RTX 4000 SFF Ada Generation delivers 19.17 TFLOPS FP32, which is 93.7% higher than the AMD Radeon RX 6650M XT's 9.896 TFLOPS. This is despite the AMD card's higher clock speeds.

Q: How do the memory capacities compare?

A: The NVIDIA card has 20 GB of GDDR6 memory, while the AMD card has 8 GB. The NVIDIA part also has a wider 160-bit bus versus the AMD's 128-bit bus, resulting in 280.0 GB/s versus 256.0 GB/s bandwidth.

Q: What is the transistor density difference?

A: The NVIDIA AD104 chip has a density of 121.8 million transistors per mm² on a 5 nm TSMC process. The AMD Navi 23 has 46.7 million per mm² on a 7 nm TSMC process. The NVIDIA chip is more than 2.6 times denser.

Q: Are these GPUs in the same performance tier?

A: No. The NVIDIA card is in the 95th percentile of all GPUs, while the AMD card is in the 91st percentile. The NVIDIA card's average benchmark score is 117,088 versus 76,904 for the AMD part.

Q: Which GPU has more RT cores?

A: The NVIDIA RTX 4000 SFF Ada Generation has 48 RT cores. The AMD Radeon RX 6650M XT has 32 RT cores. The NVIDIA card also includes 192 tensor cores, while the AMD part lists none.

Q: What is the production status of each card?

A: The NVIDIA RTX 4000 SFF Ada Generation is listed as active in production. The AMD Radeon RX 6650M XT is end-of-life. The NVIDIA card was released on 2023-03-20, while the AMD card was released on 2022-01-03.

Specification Differences

The two GPUs differ across nearly every recorded specification. The NVIDIA RTX 4000 SFF Ada Generation uses the AD104 chip on Ada Lovelace architecture, fabricated on a 5 nm TSMC process. The AMD Radeon RX 6650M XT uses Navi 23 on RDNA 2.0, on a 7 nm TSMC process.

Transistor counts are 35,800 million for the NVIDIA part and 11,060 million for the AMD part. Die sizes are 294 mm² versus 237 mm². Transistor densities are 121.8M per mm² versus 46.7M per mm².

Clock speeds differ substantially. The NVIDIA base clock is 720 MHz, boost is 1,560 MHz, and memory clock is 1750 MHz with 14 Gbps effective. The AMD base clock is 2,068 MHz, game clock is 2,162 MHz, boost is 2,416 MHz, and memory clock is 2000 MHz with 16 Gbps effective.

Memory configurations differ: 20 GB versus 8 GB, 160-bit versus 128-bit bus, and 280.0 GB/s versus 256.0 GB/s bandwidth.

Compute resources differ: 6,144 shading units versus 2,048, 192 TMUs versus 128, 64 ROPs on both, 48 RT cores versus 32, and 192 tensor cores versus none.

Throughput figures differ. Pixel rate is 99.84 GPixel/s for the NVIDIA card versus 154.6 GPixel/s for the AMD card. Texture rate is 299.5 GTexel/s versus 309.2 GTexel/s. FP32 is 19.17 TFLOPS versus 9.896 TFLOPS. FP16 is 19.17 TFLOPS (1:1) versus 19.79 TFLOPS (2:1).

Power and physical specifications differ. The NVIDIA card has a 70 W TDP, is dual-slot, has no power connectors, and suggests a 250 W PSU. The AMD card has a 120 W TDP, is IGP slot width, and has no listed PSU suggestion.

The NVIDIA card uses PCIe 4.0 x16, while the AMD card uses PCIe 4.0 x8. Display outputs are 4x mini-DisplayPort 1.4a on the NVIDIA card, versus portable-device-dependent on the AMD card.

The NVIDIA card has dimensions of 168 mm length and 69 mm height. The AMD card has no listed dimensions.

Release dates and status differ: the NVIDIA card released 2023-03-20 and is active; the AMD card released 2022-01-03 and is end-of-life.

Head-to-Head Benchmarks

The database records one head-to-head benchmark between these two GPUs. The test is Geekbench OpenCL, and the NVIDIA RTX 4000 SFF Ada Generation wins decisively.

The NVIDIA card scores 124,812, while the AMD Radeon RX 6650M XT scores 76,904. The delta percentage is 62.3% in favor of the NVIDIA card. This is a substantial margin, indicating that the NVIDIA card delivers more than one and a half times the OpenCL compute performance of the AMD part.

Looking at the broader context from the database, the NVIDIA card's average benchmark score of 117,088 places it near several other high-end parts. Its nearest rivals include the NVIDIA GB10 at 117,393 (a 0.3% difference), the AMD Radeon PRO W7700 at 118,976 (1.6% behind), the NVIDIA Tesla V100 SXM2 16 GB at 114,395 (2.4% ahead), and the NVIDIA RTX A5500 Mobile at 113,944 (2.8% ahead). These deltas show the RTX 4000 SFF sitting in a tightly contested cluster of high-performance GPUs.

The AMD card's average score of 76,904 places it near a different set of rivals. The NVIDIA GeForce RTX 5090 D scores 77,712 (1% ahead), the AMD Radeon RX 6850M XT scores 78,940 (2.6% ahead), and the NVIDIA Tesla P100 PCIe 12 GB and 16 GB score 79,396 and 79,605 respectively (3.1% and 3.4% ahead). The Radeon RX 6650M XT sits at the lower end of this group.

The 62.3% gap in the head-to-head OpenCL test is consistent with the 52.2% difference in average benchmark scores. The NVIDIA card not only wins the direct comparison but also maintains a similar proportional advantage in its overall benchmark profile. The recorded data shows no benchmark where the AMD card takes the lead.

For FP16 throughput, the AMD card actually posts a higher figure of 19.79 TFLOPS versus the NVIDIA's 19.17 TFLOPS, but this is achieved with a 2:1 ratio, meaning it uses a different execution path. The NVIDIA card maintains a 1:1 ratio for FP16 to FP32, which is typical of Ada Lovelace's design. In raw FP32, which is more commonly used in general compute workloads, the NVIDIA card is nearly double the AMD card's output.

The pixel rate and texture rate figures go the other way. The AMD card has a higher pixel rate at 154.6 GPixel/s versus 99.84 GPixel/s, and a slightly higher texture rate at 309.2 GTexel/s versus 299.5 GTexel/s. These numbers reflect the AMD card's higher clock speeds, but they do not translate into an overall benchmark win.

The memory bandwidth difference is modest, with the NVIDIA card at 280.0 GB/s versus 256.0 GB/s. However, the NVIDIA card's 20 GB capacity is a major advantage for workloads that exceed 8 GB, as the AMD card would be forced to spill to system memory or fail to allocate.

The recorded data indicates a clear overall winner in compute performance, with the NVIDIA RTX 4000 SFF Ada Generation holding a significant lead in the only direct benchmark comparison available.