GPU Comparison

FAQ

Q: How do the NVIDIA L40 and AMD Radeon RX 6650M XT compare in raw benchmark performance?

A: The recorded data shows a decisive gap. In the Geekbench OpenCL test, the NVIDIA L40 scores 330,926 points, while the AMD Radeon RX 6650M XT scores 76,904 points. That puts the L40 ahead by 330.3%, a massive margin that reflects the two products' entirely different design targets.

Q: What is the average benchmark score for each GPU?

A: The NVIDIA L40 has an average benchmark score of 284,111 across its tested workloads. The AMD Radeon RX 6650M XT has an average of 76,904, which is derived from its single recorded OpenCL result. The L40's average sits roughly 3.7 times higher than the AMD part's score.

Q: Which GPU ranks higher in the database's percentile system?

A: The NVIDIA L40 sits in the 99th percentile of all GPUs tracked by the database, meaning it outperforms nearly every other recorded part. The AMD Radeon RX 6650M XT lands in the 91st percentile, which is still strong but clearly a step below the L40's near-top-tier placement.

Q: What do the nearest rivals look like for each GPU?

A: For the NVIDIA L40, the closest competitor is the NVIDIA RTX 6000 Ada Generation with an average score of 287,237 (1.1% lower), followed by the NVIDIA L40S at 295,763 (3.9% lower). The AMD Radeon RX 6650M XT's nearest rival is the NVIDIA GeForce RTX 5090 D at 77,712 (1% lower), with the AMD Radeon RX 6850M XT close behind at 78,940 (2.6% lower). These deltas show both cards sit within a tight cluster of their respective peers.

Q: Which GPU has the higher boost clock?

A: The AMD Radeon RX 6650M XT has a higher boost clock at 2,416 MHz, while the NVIDIA L40 boosts to 2,490 MHz. Wait, checking the data again: the L40's boost is 2,490 MHz, which is actually higher. The AMD part's base clock of 2,068 MHz is substantially higher than the L40's 735 MHz base, but the L40's boost clock takes the lead.

Q: What is the memory configuration difference between the two?

A: The NVIDIA L40 packs 48 GB of GDDR6 memory on a 384-bit bus, delivering 864.0 GB/s of bandwidth. The AMD Radeon RX 6650M XT has 8 GB of GDDR6 on a 128-bit bus, providing 256.0 GB/s. The L40 offers six times the capacity and more than three times the bandwidth.

The Verdict

The data paints a clear picture: the NVIDIA L40 and AMD Radeon RX 6650M XT are not competing in the same arena. The L40 is a server-class accelerator built for compute-heavy workloads, while the RX 6650M XT is a mobile GPU designed for laptops. The 330.3% OpenCL delta is not a marginal gap; it is a chasm.

For users who need maximum compute throughput, the NVIDIA L40 is the obvious choice. Its 90.52 TFLOPS of FP32 performance, 48 GB of VRAM, and 99th percentile ranking make it suitable for AI inference, scientific simulation, and large-scale rendering tasks. The data shows it sits comfortably ahead of its own nearest rivals, including the RTX 6000 Ada Generation by 1.1% and the L40S by 3.9%. The L40 also achieves this with a 300 W TDP, which is modest for the performance class it occupies.

The AMD Radeon RX 6650M XT, by contrast, is a mobile part with a 120 W TDP and an IGP form factor. Its 91st percentile ranking is respectable for a laptop GPU, and its nearest rivals (RTX 5090 D, RX 6850M XT, Tesla P100 variants) are all within a 3.4% band, showing it is competitive within its segment. However, its 8 GB memory pool and 256.0 GB/s bandwidth limit its ceiling for large datasets.

The verdict from the data: choose the NVIDIA L40 if the workload demands server-grade compute, memory capacity, and bandwidth. Choose the AMD Radeon RX 6650M XT if the requirement is a power-efficient mobile GPU that still delivers solid OpenCL performance relative to its peer group. The two should never be cross-shopped; they serve different physical and performance tiers.

Head-to-Head Benchmarks

The single recorded head-to-head benchmark is Geekbench OpenCL, and it is not close. The NVIDIA L40 produces a score of 330,926, while the AMD Radeon RX 6650M XT manages 76,904. The delta of 330.3% means the L40 delivers roughly 4.3 times the raw compute throughput in this workload.

Context from the rivals list reinforces the L40's dominance. Its average score of 284,111 is within 1.1% of the RTX 6000 Ada Generation's 287,237, and it trails the L40S by only 3.9%. The AMD Instinct MI300X, a data center part, leads the L40 by 10.7% with a score of 317,994. This places the L40 in a tight competitive cluster at the very top of the database, even while it beats the RX 6650M XT by a factor of more than four.

For the AMD Radeon RX 6650M XT, its 76,904 OpenCL score places it in a different neighborhood entirely. Its closest rival, the NVIDIA GeForce RTX 5090 D, scores 77,712 (1% higher), and the AMD Radeon RX 6850M XT scores 78,940 (2.6% higher). The Tesla P100 variants are 3.1% and 3.4% higher respectively. These small deltas show the RX 6650M XT is a competitive mobile GPU, but the absolute numbers are an order of magnitude below the L40.

The wins tally reflects this: the L40 claims 1 win out of 1 head-to-head test, while the RX 6650M XT has 0 wins. The data is unambiguous about which GPU dominates in raw compute.

Specification Differences

The specification sheets diverge sharply across nearly every measurable field. The NVIDIA L40 uses the AD102 chip, while the AMD Radeon RX 6650M XT uses Navi 23. The L40's process node is 5 nm, compared to 7 nm for the AMD part, both from TSMC. Transistor counts differ by a factor of nearly seven: 76,300 million for the L40 versus 11,060 million for the RX 6650M XT. Die size is 609 mm² for NVIDIA and 237 mm² for AMD, giving transistor densities of 125.3M per mm² and 46.7M per mm² respectively.

Clock behavior is one area where the AMD part looks competitive on paper. The RX 6650M XT has a base clock of 2,068 MHz versus the L40's 735 MHz, and its game clock is listed at 2,162 MHz. However, the L40's boost clock of 2,490 MHz edges out the AMD's 2,416 MHz boost. Memory clocks are closer: 2,250 MHz (18 Gbps effective) for the L40 versus 2,000 MHz (16 Gbps effective) for the AMD part.

Memory configuration is a different story. The L40 offers 48 GB of GDDR6 over a 384-bit bus with 864.0 GB/s bandwidth. The RX 6650M XT has 8 GB over a 128-bit bus with 256.0 GB/s. That is a 6x capacity advantage and a 3.375x bandwidth advantage for the L40.

Compute resources are similarly lopsided. The L40 has 18,176 shading units, 568 TMUs, 192 ROPs, 142 RT cores, and 568 tensor cores. The RX 6650M XT has 2,048 shading units, 128 TMUs, 64 ROPs, and 32 RT cores, with no tensor cores listed. Pixel rate is 478.1 GPixel/s for the L40 versus 154.6 GPixel/s for the AMD. Texture rate is 1,414.3 GTexel/s versus 309.2 GTexel/s. FP32 throughput is 90.52 TFLOPS versus 9.896 TFLOPS, a 9.1x difference.

Power and form factor also separate the two. The L40 has a 300 W TDP, dual-slot width, a 1x 16-pin power connector, and a suggested PSU of 700 W. The RX 6650M XT has a 120 W TDP, is listed as IGP (integrated graphics processor in mobile), and has no power connectors. Bus interface differs: PCIe 4.0 x16 for the L40 versus PCIe 4.0 x8 for the AMD. Display outputs are 4x DisplayPort 1.4a for the L40 versus "Portable Device Dependent" for the mobile part.

Architecture Differences

The architectures reflect their respective design philosophies. The NVIDIA L40 is built on Ada Lovelace, the architecture that powers NVIDIA's server and workstation lineup. The AMD Radeon RX 6650M XT uses RDNA 2.0, a mobile-focused iteration of AMD's gaming architecture. These are not evolutionary siblings; they are fundamentally different designs optimized for different workloads.

The L40's Ada Lovelace architecture includes dedicated tensor cores (568 of them), which the RX 6650M XT lacks entirely. This makes the L40 suited for AI and machine learning tasks that rely on tensor operations. The RDNA 2.0 architecture in the AMD part has no tensor core equivalent, instead focusing on traditional shader throughput and ray tracing via its 32 RT cores.

Memory architecture differs as well. The L40 uses a 384-bit memory interface, while the RX 6650M XT is limited to 128-bit. The L40's 864.0 GB/s bandwidth is a direct result of the wider bus, and the 48 GB capacity allows large models and datasets to reside entirely in VRAM. The RX 6650M XT's 8 GB pool is typical for a mobile GPU but severely limits its utility for large compute workloads.

The feature sets are closer than the hardware suggests. Both support DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. Both are produced by TSMC, though on different nodes. The L40's predecessor is Server Ampere, and its successor is Server Hopper, indicating a clear server lineage. The RX 6650M XT's predecessor is Polaris Mobile, and it has no listed successor, marking it as a terminal mobile design.

The production status for both is end-of-life, and both were released in early 2022 (the RX 6650M XT on January 3, the L40 on October 12). The L40's generation is listed as "Server Ada (Lxx)," while the AMD part's generation is "Navi Mobile (RX 6000M)." Those labels capture the essence: one is a data center workhorse, the other a laptop component. The architecture differences are not just technical but philosophical, and the benchmark data reflects that divide.