GPU Comparison

Head-to-Head Benchmarks

The only directly comparable benchmark in the data is Geekbench OpenCL, and the result is decisively one-sided. The NVIDIA L20 scores 274,276 points against the AMD Radeon Pro W6800X's 124,498 points. That is a 120.3% delta, meaning the L20 more than doubles the W6800X's OpenCL output. In practical terms, any workload that scales linearly with raw compute throughput will finish in roughly half the time on the NVIDIA card.

The gap is so large that the two cards do not even occupy the same competitive tier in the aggregate data. The L20's average benchmark score across all tests sits at 251,147, placing it in the 99th percentile of all GPUs. The W6800X averages 160,671, which lands in the 97th percentile. While both are high-performing parts, the 90,476-point difference in average scores represents a fundamental performance chasm, not a marginal one.

Looking at the nearest rivals for each card clarifies the picture further. The L20's closest competitor is the NVIDIA PG506-232, which scores 225,124, an 11.6% deficit to the L20. The AMD Radeon PRO W7900D trails by 14.2% at 219,827. On the other side, the W6800X sits within a tight cluster: the NVIDIA A100 PCIe 40 GB is just 1.1% behind at 162,504, the AMD Radeon PRO W7800 is 2.6% ahead at 164,894, and the NVIDIA RTX A5500 is 2.8% ahead at 165,217. The W6800X's performance neighborhood is populated by cards that are nowhere near the L20's league, confirming that the head-to-head comparison is not close.

There is no reverse benchmark to analyze. The W6800X has a Geekbench Metal score of 196,844, but the L20 has no corresponding Metal result in the data, so a direct comparison on that API is impossible. Similarly, the L20 posts a Geekbench Vulkan score of 228,018, but the W6800X has no Vulkan entry. The only shared test is OpenCL, and there the verdict is unambiguous.

Where Each One Wins

The NVIDIA L20 wins the only directly comparable workload category. In OpenCL compute, it holds a 120.3% advantage over the W6800X. This makes the L20 the clear choice for any application that relies on OpenCL for general-purpose GPU compute, think scientific simulation, data processing, or rendering tasks that leverage this API. The L20's 59.35 TFLOPS of FP32 performance versus the W6800X's 16.03 TFLOPS reinforces this dominance in single-precision workloads. Even in FP16, where the W6800X's 2:1 ratio gives it a theoretical advantage in ratio terms, the L20's 59.35 TFLOPS (1:1) still exceeds the W6800X's 32.06 TFLOPS (2:1) in absolute terms.

The AMD Radeon Pro W6800X does not win any benchmark in the shared dataset. Its strengths are contextual rather than comparative. The card's Metal score of 196,844 indicates solid performance in Apple's graphics API, which is relevant given its "Radeon Pro Mac" generation label and the Apple MPX bus interface. The W6800X is designed for Mac Pro systems, where the L20 cannot even be installed without adapter complexity. The 32 GB of GDDR6 memory and 512.0 GB/s bandwidth are substantial for large datasets, and the 200 W TDP means it draws 75 W less than the L20's 275 W. For a Mac-centric workflow with moderate compute demands, the W6800X is functional; for raw performance, it is not competitive with the L20.

The percentile data tells a similar story. The L20's 99th percentile ranking among all GPUs puts it in the top 1% of all hardware ever benchmarked. The W6800X's 97th percentile is impressive but not elite. The L20 also beats its nearest rivals by double-digit percentages (11.6% over the PG506-232, 14.2% over the PRO W7900D), while the W6800X is essentially tied with its nearest competitors, all within a 3.3% band. The L20 is a leader; the W6800X is a mid-pack contender.

Architecture Differences

The architectural divide between these two GPUs is generational and fundamental. The NVIDIA L20 uses the AD102 chip built on Ada Lovelace architecture, fabricated on TSMC's 5 nm process. It packs 76,300 million transistors into a 609 mm² die, yielding a transistor density of 125.3 million per square millimeter. The AMD Radeon Pro W6800X uses the Navi 21 chip on RDNA 2.0 architecture, built on TSMC's 7 nm node. It contains 26,800 million transistors across a 520 mm² die, for a density of 51.5 million per square millimeter. The L20 achieves roughly 2.4 times the transistor density of the W6800X, a direct consequence of the newer process node.

Core configurations differ dramatically. The L20 has 11,776 shading units, 368 texture mapping units, and 128 raster operation units. It also features 92 ray tracing cores and 368 tensor cores, the latter being entirely absent from the W6800X, which has no tensor core specification at all. The W6800X counters with 3,840 shading units, 240 TMUs, and 96 ROPs, plus 60 ray tracing cores. The L20's shading unit count is over three times higher, and its TMU count is 53% higher. These raw resource differences explain the performance gap: the L20 simply has far more hardware to throw at compute problems.

Memory subsystems also diverge. The L20 uses 48 GB of GDDR6 on a 384-bit bus, delivering 864.0 GB/s of bandwidth. The W6800X has 32 GB of GDDR6 on a 256-bit bus, for 512.0 GB/s. The L20 offers 50% more memory capacity and 68.75% more bandwidth. Clock speeds tell a different story: the W6800X has a higher base clock at 1800 MHz versus the L20's 1440 MHz, and its boost clock of 2087 MHz approaches the L20's 2520 MHz boost. The L20 compensates with its massive core count and architectural efficiency. The L20's memory runs at 2250 MHz (18 Gbps effective) versus the W6800X's 2000 MHz (16 Gbps effective).

The L20 is a dual-slot card with a 16-pin power connector and a recommended 600 W PSU. The W6800X is a quad-slot card using Apple's MPX power connector, requiring a 550 W PSU. The L20 uses PCIe 4.0 x16 for connectivity, while the W6800X uses the Apple MPX bus interface. Display outputs also differ: the L20 offers four DisplayPort 1.4a connections, while the W6800X provides one HDMI 2.1 and four Thunderbolt ports. Both support DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4.

The L20 was released in November 2023 and remains in active production, with the Server Ampere generation as predecessor and Server Hopper as successor. The W6800X launched in August 2021 and is now end-of-life, with no predecessor or successor listed. Its launch MSRP was 2,799 USD.

FAQ

Q: Which GPU scores higher in OpenCL benchmarks?

A: The NVIDIA L20 scores 274,276 in Geekbench OpenCL, while the AMD Radeon Pro W6800X scores 124,498. The L20 leads by 120.3%.

Q: Does the AMD card win any shared benchmark?

A: No. The only benchmark both cards share is Geekbench OpenCL, and the NVIDIA L20 wins that test. The W6800X has a Metal score of 196,844, but the L20 has no Metal result to compare against.

Q: How do their memory specifications compare?

A: The L20 has 48 GB of GDDR6 on a 384-bit bus with 864.0 GB/s bandwidth. The W6800X has 32 GB of GDDR6 on a 256-bit bus with 512.0 GB/s bandwidth. The L20 offers more capacity and higher bandwidth.

Q: What is the transistor density difference?

A: The L20 achieves 125.3 million transistors per square millimeter on TSMC's 5 nm process with 76,300 million total transistors. The W6800X has 51.5 million per square millimeter on 7 nm with 26,800 million total transistors.

Q: Are these cards compatible with the same systems?

A: No. The L20 uses PCIe 4.0 x16 and a 16-pin power connector, while the W6800X uses the Apple MPX bus interface and power connector. The W6800X is specifically from the Radeon Pro Mac generation.

Q: What is the production status of each card?

A: The NVIDIA L20 is listed as Active production, released in November 2023. The AMD Radeon Pro W6800X is End-of-life, released in August 2021.

The Verdict

The data points to a single conclusion: the NVIDIA L20 is the superior performer in every measurable shared category. Its OpenCL score is 120.3% higher, its average benchmark score is 90,476 points higher, and it ranks in the 99th percentile of all GPUs versus the W6800X's 97th. The L20's nearest rivals are 11.6% to 14.2% behind, while the W6800X's nearest rivals are within 3.3%, meaning the W6800X is merely competitive with its peers, whereas the L20 leads its class.

Users who prioritize raw compute performance, large memory capacity (48 GB vs 32 GB), and higher bandwidth (864.0 GB/s vs 512.0 GB/s) should choose the NVIDIA L20 without hesitation. It also offers tensor cores, which the W6800X lacks entirely, making it suitable for AI and machine learning workloads that the AMD card cannot accelerate. The L20's newer 5 nm process, higher transistor density, and active production status further recommend it for long-term deployment.

The AMD Radeon Pro W6800X is only the right choice in a narrow context: Mac Pro systems that require the Apple MPX interface. Its 200 W TDP is lower than the L20's 275 W, and its Metal score of 196,844 demonstrates capable performance in Apple's ecosystem. For users locked into that platform, the W6800X is functional. But for any PCIe-based workstation or server, the L20 wins on performance, memory, features, and longevity. The W6800X is end-of-life; the L20 is active. The verdict is unambiguous: the NVIDIA L20 is the stronger GPU by a wide margin.

Specification Differences

| Specification | NVIDIA L20 | AMD Radeon Pro W6800X |

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

| 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 |

| Transistor Density | 125.3M / mm² | 51.5M / mm² |

| Base Clock | 1440 MHz | 1800 MHz |

| Boost Clock | 2520 MHz | 2087 MHz |

| 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 Performance | 59.35 TFLOPS | 16.03 TFLOPS |

| FP16 Performance | 59.35 TFLOPS (1:1) | 32.06 TFLOPS (2:1) |

| TDP | 275 W | 200 W |

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

| Power Connector | 1x 16-pin | Apple MPX |

| Suggested PSU | 600 W | 550 W |

| Bus Interface | PCIe 4.0 x16 | Apple MPX |

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

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

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

| Launch MSRP | None listed | 2,799 USD |