AMD Radeon Pro W6800X Duo vs NVIDIA L20 Comparison

The NVIDIA L20 is decisively faster than the AMD Radeon Pro W6800X Duo in shared compute benchmarks, leading by 120.6% in OpenCL and 81.5% in Vulkan. The L20 achieves an average benchmark score of 251,147, placing it in the 99th percentile of all GPUs, while the W6800X Duo averages 135,774, sitting in the 96th percentile. These results reflect fundamental architectural and specification gaps, not minor tuning differences.

Head-to-Head Benchmarks

The OpenCL test is the clearest indicator of raw compute disparity. The NVIDIA L20 scores 274,276 points, while the AMD Radeon Pro W6800X Duo manages only 124,335 points. This is a 120.6% delta in favor of the L20, meaning the NVIDIA card delivers more than double the OpenCL performance. The L20's nearest rivals in this tier — the NVIDIA L40 at 284,111 and the RTX 6000 Ada Generation at 287,237 — show that the L20 sits just 11.6% and 12.6% behind those higher-end cards, respectively, yet it still crushes the AMD part by a massive margin.

Vulkan results follow the same pattern but with a smaller gap. The L20 scores 228,018, versus 125,622 for the W6800X Duo, a delta of 81.5%. Interestingly, the AMD card's Vulkan score is nearly identical to its OpenCL score (125,622 vs 124,335), suggesting its performance ceiling is consistent across these APIs. The L20, however, shows a 46,258-point drop from OpenCL to Vulkan, yet still maintains a commanding lead. The W6800X Duo's closest rival, the AMD Radeon PRO W6800, scores 135,396 — a mere 0.3% difference — while the NVIDIA A10M and RTX 4000 Ada Generation sit within 0.4% at 135,230 and 135,218, respectively. This places the W6800X Duo firmly in a midrange compute tier, whereas the L20 operates in a class above.

The L20 also wins the overall benchmark count 2–0, with no test in the shared suite where the AMD card comes out ahead. The average benchmark score difference — 251,147 versus 135,774 — translates to an 85% advantage for the L20, reinforcing that the head-to-head deltas are not outliers but representative of the entire performance profile.

Architecture Differences

The two cards are built on entirely different silicon philosophies. The NVIDIA L20 uses the AD102 chip with an Ada Lovelace architecture, manufactured on a 5 nm process at TSMC. It packs 76,300 million transistors into a 609 mm² die, yielding a transistor density of 125.3 million per mm². In contrast, the AMD Radeon Pro W6800X Duo relies on the Navi 21 chip with RDNA 2.0 architecture, built on a 7 nm process, also at TSMC. This older node houses just 26,800 million transistors on a 520 mm² die, resulting in a density of only 51.5 million per mm². The L20's newer process node and denser design give it a structural advantage before clock speeds even enter the equation.

Clock behavior differs significantly. The AMD card has a higher base clock at 1800 MHz versus 1440 MHz for the L20, but the NVIDIA part boosts much more aggressively to 2520 MHz, compared to 1967 MHz for the AMD. This 553 MHz boost advantage is substantial, allowing the L20 to sustain higher performance under load. Memory clocks also favor NVIDIA: the L20 runs at 2250 MHz with 18 Gbps effective, while the W6800X Duo operates at 2000 MHz with 16 Gbps effective.

The L20's compute resources dwarf the AMD card's. It features 11,776 shading units, 368 TMUs, 128 ROPs, 92 RT cores, and 368 tensor cores. The W6800X Duo counters with 3,840 shading units, 240 TMUs, 96 ROPs, and 60 RT cores — with no tensor cores at all. This translates to a raw FP32 throughput of 59.35 TFLOPS for the L20 versus 15.11 TFLOPS for the AMD card, a 3.9x difference. In FP16, the L20 delivers 59.35 TFLOPS at a 1:1 ratio, while the AMD part reaches 30.21 TFLOPS at a 2:1 ratio, meaning the NVIDIA card also leads in half-precision work.

Memory configurations reinforce the performance gap. The L20 offers 48 GB of GDDR6 on a 384-bit bus, delivering 864.0 GB/s of bandwidth. The W6800X Duo provides 32 GB of GDDR6 on a 256-bit bus, with 512.0 GB/s. That is a 352 GB/s bandwidth deficit for the AMD card, which matters for memory-bound workloads. The L20 also benefits from a PCIe 4.0 x16 interface, while the AMD card uses an Apple MPX bus, limiting its usability outside of Mac Pro systems.

FAQ

Q: Which card has a higher average benchmark score, and by how much?

A: The NVIDIA L20 averages 251,147, while the AMD Radeon Pro W6800X Duo averages 135,774. This represents an 85% advantage for the L20.

Q: Are there any benchmarks where the AMD card wins?

A: No. In the shared head-to-head tests (OpenCL and Vulkan), the NVIDIA L20 wins both, with 0 wins for the AMD card.

Q: How does the AMD card compare to its closest rivals?

A: The W6800X Duo is within 0.5% of the AMD Radeon PRO V620 (136,472), and within 0.4% of the NVIDIA A10M (135,230) and RTX 4000 Ada Generation (135,218). It essentially ties its nearest competition.

Q: What is the process node difference between the two?

A: The NVIDIA L20 uses a 5 nm TSMC process, while the AMD Radeon Pro W6800X Duo uses a 7 nm TSMC process. The L20's die density is 125.3M transistors per mm² versus 51.5M for the AMD card.

Q: Does the AMD card support tensor cores?

A: No. The W6800X Duo has no tensor cores, whereas the NVIDIA L20 includes 368 tensor cores.

Q: What is the launch MSRP of the AMD card?

A: The AMD Radeon Pro W6800X Duo had a launch MSRP of 4,999 USD.

Specification Differences

| Specification | NVIDIA L20 | AMD Radeon Pro W6800X Duo |

|---|---|---|

| Architecture | Ada Lovelace | RDNA 2.0 |

| Process Node | 5 nm | 7 nm |

| Transistors | 76,300 million | 26,800 million |

| Die Size | 609 mm² | 520 mm² |

| Base Clock | 1440 MHz | 1800 MHz |

| Boost Clock | 2520 MHz | 1967 MHz |

| Memory Clock | 2250 MHz (18 Gbps effective) | 2000 MHz (16 Gbps effective) |

| Memory Size | 48 GB | 32 GB |

| Memory Bus | 384 bit | 256 bit |

| Memory Bandwidth | 864.0 GB/s | 512.0 GB/s |

| Shading Units | 11776 | 3840 |

| TMUs | 368 | 240 |

| ROPs | 128 | 96 |

| RT Cores | 92 | 60 |

| Tensor Cores | 368 | None |

| FP32 | 59.35 TFLOPS | 15.11 TFLOPS |

| FP16 | 59.35 TFLOPS (1:1) | 30.21 TFLOPS (2:1) |

| TDP | 275 W | 400 W |

| Slot Width | Dual-slot | Quad-slot |

| Bus Interface | PCIe 4.0 x16 | Apple MPX |

| Display Outputs | 4x DisplayPort 1.4a | 1x HDMI 2.1, 4x Thunderbolt |

| Production Status | Active | End-of-life |

| Release Date | 2023-11-15 | 2021-08-02 |

The Verdict

The data is unambiguous: the NVIDIA L20 is the superior GPU for raw compute performance. It leads by 120.6% in OpenCL and 81.5% in Vulkan, holds a 99th percentile ranking versus the AMD card's 96th, and offers nearly four times the FP32 throughput (59.35 TFLOPS vs 15.11 TFLOPS). The L20 achieves this while drawing 275 W, compared to 400 W for the AMD card, and fits in a dual-slot form factor versus the AMD's quad-slot design. For any workload that relies on OpenCL or Vulkan compute, the L20 is simply in a different league.

The AMD Radeon Pro W6800X Duo is not without merit, but its strengths are contextual. It matches its nearest rivals almost exactly — within 0.5% of the Radeon PRO V620 and 0.4% of the NVIDIA A10M — indicating it is a competent midrange card. Its 2:1 FP16 ratio (30.21 TFLOPS) provides a boost for half-precision tasks, and its 1x HDMI 2.1 plus 4x Thunderbolt outputs make it purpose-built for Mac Pro display configurations. However, its Apple MPX bus interface restricts it to that ecosystem, and its end-of-life production status means no future support or availability guarantees.

The verdict is straightforward: the NVIDIA L20 wins on every shared benchmark, every compute metric, and every efficiency figure. The only scenario where the AMD card makes sense is if the target system is a Mac Pro and the workload is display-centric rather than compute-heavy. For general compute, the L20 is the clear choice.

Where Each One Wins

NVIDIA L20: The L20 dominates in OpenCL, where its 274,276 score is 120.6% higher than the AMD card's 124,335. It also wins Vulkan with 228,018 versus 125,622, an 81.5% margin. The L20's 48 GB memory capacity and 864.0 GB/s bandwidth suit large dataset processing, and its 368 tensor cores provide dedicated AI acceleration that the AMD card lacks entirely. Its 5 nm process and 2520 MHz boost clock make it the more efficient and faster option for sustained compute. The 275 W TDP means it can be deployed in dual-slot configurations where space and power are constrained.

AMD Radeon Pro W6800X Duo: The AMD card wins in FP16 efficiency relative to its FP32 output, delivering 30.21 TFLOPS at a 2:1 ratio, which is double its FP32 rate. It also offers a distinct display output set — 1x HDMI 2.1 and 4x Thunderbolt — versus the L20's 4x DisplayPort 1.4a, making it the better fit for Mac Pro setups with Thunderbolt peripherals. Its higher base clock (1800 MHz vs 1440 MHz) suggests better low-load responsiveness, and its 32 GB memory is sufficient for many professional workflows. The 4,999 USD launch MSRP, however, does not translate into any benchmark advantage in shared tests. The AMD card's nearest rival performance — within 0.4% of the RTX 4000 Ada Generation — indicates it is competitive in its own tier, but that tier is far below the L20's.