AMD Radeon Pro W6800X Duo vs NVIDIA L40 Comparison

NVIDIA L40 and AMD Radeon Pro W6800X Duo are both professional workstation GPUs, but they target fundamentally different ecosystems and performance tiers. The L40 is a server-class accelerator built on Ada Lovelace, while the W6800X Duo is a dual-GPU Mac Pro module based on RDNA 2.0. Benchmark data shows a stark performance gap, with the L40 dominating in compute workloads, yet the W6800X Duo holds a distinct niche for Apple-centric workflows. The L40 achieves an average benchmark score of 284,111, placing it in the 99th percentile of all GPUs, while the W6800X Duo scores 135,774, landing in the 96th percentile. This 148,337-point gap (roughly 109% higher average) underscores that these are not direct competitors in raw throughput, but rather solutions for different professional environments.

Where Each One Wins

The NVIDIA L40 wins decisively in every head-to-head benchmark recorded. In Geekbench OpenCL, it scores 330,926 against the W6800X Duo’s 124,335, a 166.2% advantage. In Geekbench Vulkan, the L40 scores 237,295 versus 125,622, an 88.9% lead. These are not marginal wins; they represent a dominant performance class difference. The L40’s compute architecture, with 18,176 shading units and 568 tensor cores, is built for massive parallel workloads, AI inference, and rendering tasks that scale across CUDA cores. Its 48 GB of GDDR6 memory with 864.0 GB/s bandwidth provides a substantial buffer for large datasets and high-resolution textures.

The AMD Radeon Pro W6800X Duo wins in compatibility and form factor within Apple’s Mac Pro ecosystem. It uses the Apple MPX bus interface, meaning it is designed to slot directly into Mac Pro systems, and its display outputs include 1x HDMI 2.1 and 4x Thunderbolt—a configuration tailored for Apple displays and peripherals. It also carries a launch MSRP of 4,999 USD, which is a data point for cost reference, though the L40 has no listed MSRP in the pack. The W6800X Duo’s dual-GPU design (implied by the “Duo” name and its 400 W TDP) provides 32 GB of combined GDDR6 memory, and its FP16 performance of 30.21 TFLOPS (2:1 ratio) is notably higher than its FP32 throughput, suggesting optimization for certain half-precision workloads, though this does not translate into competitive OpenCL or Vulkan scores.

FAQ

Q: Which GPU has the higher average benchmark score?

A: The NVIDIA L40 scores 284,111 on average, while the AMD Radeon Pro W6800X Duo scores 135,774. The L40 is roughly 109% higher, placing it in the 99th percentile compared to the W6800X Duo’s 96th.

Q: How do they compare in OpenCL performance specifically?

A: In Geekbench OpenCL, the L40 scores 330,926, which is 166.2% higher than the W6800X Duo’s 124,335. This is the largest performance delta between the two cards.

Q: Is the W6800X Duo competitive in any benchmark?

A: No, the data shows the L40 wins both head-to-head tests (OpenCL and Vulkan). The W6800X Duo’s closest rival is the AMD Radeon PRO W6800, where it is only 0.3% ahead, indicating it does not even lead its own product stack significantly.

Q: What is the memory configuration difference?

A: The L40 has 48 GB of GDDR6 memory on a 384-bit bus, delivering 864.0 GB/s bandwidth. The W6800X Duo has 32 GB of GDDR6 on a 256-bit bus, delivering 512.0 GB/s bandwidth.

Q: Which card has a higher power requirement?

A: The W6800X Duo has a TDP of 400 W and a suggested PSU of 800 W, while the L40 has a TDP of 300 W and a suggested PSU of 700 W. Despite the lower TDP, the L40 delivers significantly higher performance.

Q: Are both cards still in production?

A: No, both are listed as end-of-life in the data. The L40 was released on 2022-10-12, and the W6800X Duo was released on 2021-08-02.

Head-to-Head Benchmarks

The Geekbench OpenCL test reveals the most extreme performance disparity. The NVIDIA L40 posts 330,926 points, while the AMD Radeon Pro W6800X Duo manages only 124,335. The 166.2% delta means the L40 is more than 2.6 times faster in this compute-heavy workload. This is consistent with the L40’s architecture: 18,176 shading units operating at a boost clock of 2490 MHz produce 90.52 TFLOPS of FP32 performance, while the W6800X Duo’s 3,840 shading units at 1967 MHz yield only 15.11 TFLOPS FP32. The L40’s texture rate of 1,414.3 GTexel/s and pixel rate of 478.1 GPixel/s dwarf the W6800X Duo’s 472.1 GTexel/s and 188.8 GPixel/s, respectively.

In Geekbench Vulkan, the gap narrows but remains overwhelming. The L40 scores 237,295, and the W6800X Duo scores 125,622, a 88.9% lead for the NVIDIA card. The Vulkan test often stresses driver overhead and async compute, areas where NVIDIA’s mature server drivers likely excel. The W6800X Duo’s FP16 throughput of 30.21 TFLOPS (2:1 ratio) is double its FP32 rate, but this does not translate into Vulkan gains, as the L40 still wins decisively. The L40’s nearest rivals in average score include the NVIDIA L40S at 295,763 (3.9% higher) and AMD Instinct MI300X at 317,994 (10.7% higher), showing it sits just below the top-tier accelerators. Conversely, the W6800X Duo’s nearest rivals are all within 0.5% of its score, indicating it is tightly clustered with mid-range workstation cards like the NVIDIA RTX 4000 Ada Generation.

Specification Differences

The core specifications diverge sharply. The L40 uses 76,300 million transistors on a 609 mm² die, fabricated on TSMC’s 5 nm process, yielding a density of 125.3 million transistors per mm². The W6800X Duo uses 26,800 million transistors on a 520 mm² die, on TSMC’s 7 nm process, with a density of 51.5 million per mm². The L40’s newer node and larger transistor budget allow for 18,176 shading units, 568 TMUs, and 192 ROPs, versus the W6800X Duo’s 3,840 shading units, 240 TMUs, and 96 ROPs.

Clock speeds tell a different story: the W6800X Duo has a base clock of 1800 MHz and boost of 1967 MHz, while the L40 has a lower base of 735 MHz but a higher boost of 2490 MHz. The L40 compensates with a massive shader count. Memory also differs: the L40 has 48 GB GDDR6 at 18 Gbps effective on a 384-bit bus (864.0 GB/s), while the W6800X Duo has 32 GB GDDR6 at 16 Gbps effective on a 256-bit bus (512.0 GB/s). The W6800X Duo lacks tensor cores entirely, while the L40 includes 568 of them. Power profiles differ, with the L40 at 300 W and the W6800X Duo at 400 W, though the W6800X Duo uses an Apple MPX interface versus the L40’s PCIe 4.0 x16. Physical size is similar in length (267 mm), but the W6800X Duo is taller at 120 mm versus 111 mm, and it is quad-slot versus the L40’s dual-slot design.

Architecture Differences

The NVIDIA L40 is built on Ada Lovelace architecture, the successor to Server Ampere. It uses a 5 nm process with 76,300 million transistors on a 609 mm² die. The architecture includes dedicated RT cores (142) and tensor cores (568), enabling hardware-accelerated ray tracing and AI workloads. Its FP32 and FP16 performance are both 90.52 TFLOPS, indicating a 1:1 ratio for compute tasks. The L40 supports DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4, and it has 4x DisplayPort 1.4a outputs.

The AMD Radeon Pro W6800X Duo uses RDNA 2.0 architecture, part of the Radeon Pro Mac (Navi II Series) generation. It is built on a 7 nm process with 26,800 million transistors on a 520 mm² die. It has 60 RT cores but no tensor cores, reflecting a focus on graphics rather than AI compute. Its FP16 performance is 30.21 TFLOPS (2:1 ratio), which is double its FP32 of 15.11 TFLOPS, a design choice for certain graphics effects. The W6800X Duo also supports DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4, but its display outputs are tailored for Apple: 1x HDMI 2.1 and 4x Thunderbolt. The architecture differences explain the benchmark gap—Ada Lovelace’s higher transistor density and dedicated tensor hardware give it a compute advantage that RDNA 2.0’s lower density and lack of tensor cores cannot overcome.

The Verdict

The data is unambiguous: the NVIDIA L40 is the superior compute performer. It wins both head-to-head benchmarks by margins of 88.9% to 166.2%, holds a 99th percentile rank versus 96th, and delivers nearly double the average benchmark score. For professionals running OpenCL or Vulkan workloads—whether for rendering, simulation, or machine learning—the L40 is the clear choice. Its 48 GB memory capacity and 864.0 GB/s bandwidth also provide more headroom for large models or datasets. The L40’s dual-slot form factor and PCIe 4.0 x16 interface make it a straightforward fit for standard server chassis.

The AMD Radeon Pro W6800X Duo is only preferable if the target system is a Mac Pro. Its Apple MPX interface and Thunderbolt outputs are non-negotiable for that platform, and its 32 GB memory is sufficient for many graphics tasks. However, its performance is not competitive with the L40, and its 400 W TDP with an 800 W PSU suggestion makes it a power-hungry option. The W6800X Duo’s closest rivals are cards like the NVIDIA RTX 4000 Ada Generation (0.4% faster) and AMD Radeon PRO W6800 (0.3% slower), meaning it does not even lead its own segment. If the workload can run on either card, the L40 is the only rational choice based on benchmark results. If the system is a Mac Pro and the workload is graphics-centric, the W6800X Duo is the only option in this comparison, but buyers should expect significantly lower compute throughput.