AMD Radeon Pro W6800X Duo vs NVIDIA L40S Comparison

The NVIDIA L40S and AMD Radeon Pro W6800X Duo occupy very different positions in the GPU landscape, as reflected in their benchmark data. The L40S is a server-oriented Ada Lovelace part, while the W6800X Duo is a Mac-specific RDNA 2.0 dual-GPU design. Their average benchmark scores—295,763 for the L40S and 135,774 for the W6800X Duo—place them far apart in overall performance, with the L40S ranking in the 99th percentile of all GPUs versus the 96th percentile for the AMD card. The head-to-head data, however, tells a more specific story about where each card excels.

Head-to-Head Benchmarks

The two GPUs share two benchmark tests in the data: Geekbench OpenCL and Geekbench Vulkan. In both, the NVIDIA L40S wins decisively. In OpenCL, the L40S scores 330,727 against 124,335 for the W6800X Duo, a delta of 166%. That is more than two and a half times the AMD card’s score, indicating a massive advantage in compute workloads that leverage OpenCL. The Vulkan result is closer but still lopsided: the L40S scores 260,799 versus 125,622, a 107.6% delta. In both tests, the win count is 2–0 in favor of NVIDIA.

These deltas are not marginal. A 166% lead in OpenCL suggests the L40S is in a different performance class for generic compute, while the 107.6% Vulkan gap shows it also dominates in cross-platform graphics and compute APIs. The W6800X Duo’s best showing in these shared tests is its Vulkan score, which reaches 125,622—still less than half of the L40S’s Vulkan score. The data shows no test where the AMD card wins, so any analysis of where the W6800X Duo might be preferable must rely on its architecture and feature set rather than raw benchmark wins.

The Verdict

From the benchmark data alone, the NVIDIA L40S is the clear choice for anyone prioritizing raw compute and graphics performance in OpenCL or Vulkan workloads. Its average score of 295,763 is 118% higher than the W6800X Duo’s 135,774. The L40S also sits in the 99th percentile of all GPUs, while the AMD card is in the 96th. For tasks that depend on these APIs—such as rendering, simulation, or machine learning inference—the L40S is categorically faster.

The AMD Radeon Pro W6800X Duo, however, has its own niche. It is built for Apple’s MPX bus interface, meaning it is designed for Mac Pro systems. If the target platform is a Mac, the W6800X Duo is the only option among the two that fits that ecosystem without adapters or compatibility workarounds. Its 32 GB of GDDR6 memory and 512.0 GB/s bandwidth are ample for many professional workflows, and its Metal benchmark score of 157,365 (not present in the shared tests) suggests it has strengths in Apple’s native graphics API. The verdict from the data is straightforward: the L40S wins on performance, but the W6800X Duo wins on platform compatibility for Mac users.

Architecture Differences

The two GPUs are built on fundamentally different architectures. The NVIDIA L40S uses the AD102 chip with Ada Lovelace architecture, fabricated on a 5 nm process at TSMC. It packs 76,300 million transistors on a 609 mm² die, yielding a transistor density of 125.3 million per mm². In contrast, the AMD Radeon Pro W6800X Duo uses the Navi 21 chip with RDNA 2.0 architecture, also from TSMC but on a 7 nm process. It contains 26,800 million transistors on a 520 mm² die, with a density of 51.5 million per mm². The L40S has nearly three times the transistor count despite a die that is only 17% larger, reflecting the denser 5 nm node.

Core counts differ dramatically. The L40S has 18,176 shading units, 568 texture mapping units, and 192 ROPs. It also includes 142 ray tracing cores and 568 tensor cores. The W6800X Duo, despite its name, has only 3,840 shading units, 240 TMUs, and 96 ROPs. It has 60 ray tracing cores and no tensor cores at all. The L40S’s tensor core count is a key architectural differentiator, enabling AI and deep learning workloads that the AMD card cannot accelerate in hardware. Both GPUs support DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4, but the L40S adds NVIDIA-specific features like tensor core acceleration, while the W6800X Duo relies on RDNA 2.0’s compute units.

Specification Differences

The specification table reveals several key differences beyond architecture. The L40S has 48 GB of GDDR6 memory on a 384-bit bus, delivering 864.0 GB/s of bandwidth. The W6800X Duo has 32 GB of GDDR6 on a 256-bit bus, with 512.0 GB/s bandwidth. The L40S’s base clock is 1110 MHz with a boost of 2520 MHz, while the AMD card runs at a higher base of 1800 MHz and a boost of 1967 MHz, but the NVIDIA card’s higher core count more than compensates for the clock disadvantage. Memory clock also differs: the L40S runs at 2250 MHz (18 Gbps effective), while the W6800X Duo runs at 2000 MHz (16 Gbps effective).

Pixel and texture rates show the L40S’s advantage: 483.8 GPixel/s and 1,431.4 GTexel/s versus 188.8 GPixel/s and 472.1 GTexel/s for the AMD card. FP32 compute is 91.61 TFLOPS for the L40S versus 15.11 TFLOPS for the W6800X Duo. The AMD card does have a higher FP16 rate of 30.21 TFLOPS (2:1 ratio), but the L40S matches its FP32 rate at 91.61 TFLOPS (1:1), making it vastly superior for half-precision work. Power draw also differs: the L40S is rated at 300 W with a suggested 700 W PSU, while the W6800X Duo draws 400 W and suggests an 800 W PSU. The L40S is dual-slot with a 1x 16-pin connector, while the W6800X Duo is quad-slot with no specified power connector and uses the Apple MPX bus interface. Display outputs differ: the L40S has 1x HDMI 2.1 and 3x DisplayPort 1.4a, while the W6800X Duo has 1x HDMI 2.1 and 4x Thunderbolt.

FAQ

Q: Which GPU has a higher average benchmark score?

A: The NVIDIA L40S has an average benchmark score of 295,763, while the AMD Radeon Pro W6800X Duo averages 135,774. The L40S also ranks in the 99th percentile of all GPUs, versus the 96th for the AMD card.

Q: How does the L40S compare to the W6800X Duo in OpenCL performance?

A: In Geekbench OpenCL, the L40S scores 330,727 versus 124,335 for the W6800X Duo, a 166% delta in favor of NVIDIA. This is the largest performance gap between the two in any shared test.

Q: Does the W6800X Duo have any benchmark advantage?

A: In the shared head-to-head tests, the W6800X Duo wins no benchmarks. However, it has a Geekbench Metal score of 157,365, which is not part of the head-to-head comparison but indicates its performance in Apple’s Metal API.

Q: What is the memory configuration difference?

A: The L40S has 48 GB of GDDR6 memory on a 384-bit bus with 864.0 GB/s bandwidth. The W6800X Duo has 32 GB of GDDR6 on a 256-bit bus with 512.0 GB/s bandwidth.

Q: Which GPU is better for AI workloads?

A: The L40S includes 568 tensor cores, which are designed for AI and deep learning acceleration. The W6800X Duo has no tensor cores, so the L40S is the only one of the two with hardware support for such tasks.

Q: What are the power requirements?

A: The L40S has a TDP of 300 W and suggests a 700 W PSU. The W6800X Duo has a TDP of 400 W and suggests an 800 W PSU. The L40S is dual-slot, while the W6800X Duo is quad-slot.

Where Each One Wins

The NVIDIA L40S wins in every shared benchmark category. Its OpenCL score of 330,727 is 166% higher than the AMD card’s, and its Vulkan score of 260,799 is 107.6% higher. This makes it the clear choice for compute-heavy tasks like scientific simulation, data processing, or any workload that scales with FP32 throughput—the L40S delivers 91.61 TFLOPS versus 15.11 TFLOPS for the W6800X Duo. The L40S’s 48 GB memory capacity and 864.0 GB/s bandwidth also make it suitable for large datasets, while its tensor cores enable AI inference and training that the AMD card cannot accelerate.

The AMD Radeon Pro W6800X Duo wins on platform fit. Its Apple MPX bus interface and Thunderbolt display outputs make it the only option for Mac Pro systems without modification. Its Metal score of 157,365, while lower than the L40S’s OpenCL and Vulkan scores, shows it has respectable performance in Apple’s native API. The W6800X Duo also has a higher base clock of 1800 MHz, which may benefit latency-sensitive tasks, and its 400 W TDP is higher, suggesting it is built to sustain heavy loads in a Mac chassis. For users locked into the Mac ecosystem, the W6800X Duo is the practical choice, despite its benchmark deficits. For everyone else, the L40S dominates the data.