AMD Radeon Pro W6900X vs NVIDIA A100 PCIe 40 GB Comparison

AMD Radeon Pro W6900X and NVIDIA A100 PCIe 40 GB are both end-of-life workstation and server accelerators that occupy the 97th percentile of all GPUs, yet their benchmark profiles reveal a fascinating split. The data shows two very different design philosophies: one optimized for graphical compute and the other for massive parallel throughput. While their average benchmark scores are remarkably close—the AMD card averages 168,574 versus the NVIDIA card’s 162,504—the individual test results tell a story of divergent strengths that potential buyers must weigh carefully.

Head-to-Head Benchmarks

The two cards split their head-to-head benchmark wins evenly, with one victory apiece, but the magnitude of those victories is anything but symmetric. The most striking result comes from the Geekbench OpenCL test, where the NVIDIA A100 PCIe 40 GB delivers a commanding 178,627 score against the AMD Radeon Pro W6900X’s 130,035. This represents a 27.2% advantage for the NVIDIA card, a massive gap that speaks to the A100’s raw compute horsepower in general-purpose workloads. The A100’s lead here is so substantial that it dwarfs every other comparison in the data, suggesting that for OpenCL-heavy applications, the NVIDIA card is in a different league entirely.

However, the AMD Radeon Pro W6900X strikes back in the Geekbench Vulkan test, posting a score of 148,865 against the A100’s 146,380. While this 1.7% margin is narrow, it is a meaningful win for AMD, particularly because Vulkan is a modern graphics API that benefits from the W6900X’s RDNA 2.0 architecture. The data implies that the AMD card handles graphics-oriented compute tasks more efficiently, even though its overall compute ceiling is lower. This pattern is reinforced when examining the broader benchmark landscape: the W6900X’s average score of 168,574 is 3.7% higher than the A100’s 162,504, yet that average is buoyed by the AMD card’s strong Geekbench Metal score of 226,821—a test the A100 does not even participate in.

Looking at the nearest rivals provides additional context. The W6900X sits just 1.5% above the NVIDIA RTX 4500 Ada Generation and 2% above the RTX A5500, while the A100 trails those same cards by 2.2% and 1.6%, respectively. This suggests that the A100’s OpenCL dominance does not translate to universal superiority, as it actually underperforms several other NVIDIA workstation cards in aggregate scoring. The W6900X, by contrast, edges out all of its nearest rivals, including the A100, making it the stronger all-around performer in this comparison despite losing the OpenCL battle so decisively.

Architecture Differences

The architectural divide between these two cards is profound, starting with their fundamental silicon designs. The AMD Radeon Pro W6900X uses the Navi 21 chip built on RDNA 2.0 architecture, manufactured by TSMC on a 7 nm process. This chip contains 26,800 million transistors packed into a 520 mm² die, resulting in a transistor density of 51.5 million per square millimeter. In contrast, the NVIDIA A100 PCIe 40 GB employs the GA100 chip on Ampere architecture, also fabricated by TSMC at 7 nm, but with a far larger 826 mm² die housing 54,200 million transistors—a density of 65.6 million per square millimeter. The A100’s die is 58.8% larger and packs more than double the transistor count, indicating a fundamentally different approach to compute density.

Memory architecture further separates these cards. The W6900X features 32 GB of GDDR6 memory on a 256-bit bus, delivering 512.0 GB/s of bandwidth. The A100 counters with 40 GB of HBM2e memory on a massive 5120-bit bus, achieving 1.56 TB/s of bandwidth—three times the memory bandwidth of the AMD card. This disparity is critical for data-intensive workloads, where the A100’s HBM2e provides a substantial advantage in feeding its compute units. The W6900X’s memory runs at 2000 MHz with 16 Gbps effective speed, while the A100’s memory operates at 1215 MHz with 2.4 Gbps effective speed, but the A100’s wider bus more than compensates.

Compute unit configurations also diverge sharply. The W6900X has 5,120 shading units, 320 texture mapping units, and 128 ROPs, along with 80 ray tracing cores. The A100 offers 6,912 shading units, 432 TMUs, and 160 ROPs, but notably has no dedicated ray tracing cores; instead, it includes 432 tensor cores for AI acceleration. Clock speeds reflect their different purposes: the W6900X runs at a base of 1825 MHz and boosts to 2171 MHz, while the A100 operates at just 765 MHz base and 1410 MHz boost. Despite the A100’s higher unit counts, the W6900X’s higher clocks yield a pixel rate of 277.9 GPixel/s and texture rate of 694.7 GTexel/s, both exceeding the A100’s 225.6 GPixel/s and 609.1 GTexel/s. In raw FP32 compute, the W6900X achieves 22.23 TFLOPS versus the A100’s 19.49 TFLOPS, but the A100 crushes FP16 with 77.97 TFLOPS (4:1) against the W6900X’s 44.46 TFLOPS (2:1).

FAQ

Q: Which card has the higher average benchmark score?

A: The AMD Radeon Pro W6900X has the higher average benchmark score at 168,574, which is 3.7% above the NVIDIA A100 PCIe 40 GB’s 162,504. This puts the W6900X in the 97th percentile of all GPUs, matching the A100’s percentile ranking.

Q: How do the two cards compare in OpenCL performance?

A: The NVIDIA A100 PCIe 40 GB is decisively ahead in OpenCL, scoring 178,627 versus the AMD Radeon Pro W6900X’s 130,035. This represents a 27.2% advantage for the A100, the largest performance gap between the two cards in any benchmark.

Q: Does the AMD card win any head-to-head tests?

A: Yes, the AMD Radeon Pro W6900X wins the Geekbench Vulkan test with a score of 148,865, narrowly beating the NVIDIA A100 PCIe 40 GB’s 146,380 by 1.7%. This shows the AMD card’s strength in graphics-oriented APIs.

Q: What memory capacities and types do these cards use?

A: The AMD Radeon Pro W6900X uses 32 GB of GDDR6 memory on a 256-bit bus with 512.0 GB/s bandwidth. The NVIDIA A100 PCIe 40 GB uses 40 GB of HBM2e memory on a 5120-bit bus with 1.56 TB/s bandwidth.

Q: Which card has higher clock speeds?

A: The AMD Radeon Pro W6900X has significantly higher clocks, with a base of 1825 MHz and boost of 2171 MHz. The NVIDIA A100 PCIe 40 GB operates at a much lower 765 MHz base and 1410 MHz boost, reflecting its focus on sustained compute rather than peak graphics performance.

Q: Are both cards still in production?

A: No, both the AMD Radeon Pro W6900X and NVIDIA A100 PCIe 40 GB are marked as end-of-life in the production status data.

Specification Differences

| Specification | AMD Radeon Pro W6900X | NVIDIA A100 PCIe 40 GB |

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

| Chip | Navi 21 | GA100 |

| Architecture | RDNA 2.0 | Ampere |

| Transistors | 26,800 million | 54,200 million |

| Die Size | 520 mm² | 826 mm² |

| Transistor Density | 51.5M / mm² | 65.6M / mm² |

| Base Clock | 1825 MHz | 765 MHz |

| Boost Clock | 2171 MHz | 1410 MHz |

| Memory Size | 32 GB | 40 GB |

| Memory Type | GDDR6 | HBM2e |

| Memory Bus | 256 bit | 5120 bit |

| Memory Bandwidth | 512.0 GB/s | 1.56 TB/s |

| Shading Units | 5120 | 6912 |

| TMUs | 320 | 432 |

| ROPs | 128 | 160 |

| RT Cores | 80 | null |

| Tensor Cores | null | 432 |

| Pixel Rate | 277.9 GPixel/s | 225.6 GPixel/s |

| Texture Rate | 694.7 GTexel/s | 609.1 GTexel/s |

| FP32 | 22.23 TFLOPS | 19.49 TFLOPS |

| FP16 | 44.46 TFLOPS (2:1) | 77.97 TFLOPS (4:1) |

| TDP | 300 W | 250 W |

| Suggested PSU | 700 W | 600 W |

| Bus Interface | Apple MPX | PCIe 4.0 x16 |

| Display Outputs | 1x HDMI 2.1, 4x Thunderbolt | No outputs |

| Slot Width | null | Dual-slot |

| Power Connectors | null | 8-pin EPS |

| Dimensions (LxH) | 267 mm x 120 mm | 267 mm x 111 mm |

Where Each One Wins

The AMD Radeon Pro W6900X wins in aggregate performance, with its average benchmark score of 168,574 standing 3.7% above the A100. It also claims victory in the Vulkan benchmark, where its 148,865 score edges out the A100 by 1.7%. The W6900X further excels in graphics-specific metrics: its pixel rate of 277.9 GPixel/s and texture rate of 694.7 GTexel/s both surpass the A100’s corresponding figures, and its FP32 compute of 22.23 TFLOPS exceeds the A100’s 19.49 TFLOPS. For display-centric work, the W6900X offers 1x HDMI 2.1 and 4x Thunderbolt outputs, while the A100 provides no display outputs at all. The AMD card also achieves a massive Geekbench Metal score of 226,821, a benchmark where the A100 has no recorded result.

The NVIDIA A100 PCIe 40 GB wins decisively in OpenCL, delivering 178,627 versus the W6900X’s 130,035—a 27.2% advantage that dominates this comparison. The A100 also excels in memory capacity and bandwidth, offering 40 GB of HBM2e with 1.56 TB/s throughput versus the W6900X’s 32 GB and 512.0 GB/s. For FP16 workloads, the A100’s 77.97 TFLOPS more than doubles the W6900X’s 44.46 TFLOPS, and its 432 tensor cores provide dedicated AI acceleration hardware absent from the AMD card. The A100’s lower TDP of 250 W versus 300 W, combined with its 600 W suggested PSU versus 700 W, also makes it more power-efficient on paper.

The Verdict

The data presents a clear choice based on workload priorities. If the primary use case involves OpenCL compute, AI inference, or massive memory bandwidth demands, the NVIDIA A100 PCIe 40 GB is the superior option—its 27.2% OpenCL lead and 1.56 TB/s memory bandwidth are decisive advantages that the W6900X cannot counter. The A100’s 40 GB of HBM2e and 432 tensor cores make it the obvious selection for machine learning and data-intensive scientific computing, despite its lower clock speeds and FP32 performance.

Conversely, if the workload spans graphics rendering, Vulkan-based applications, or general-purpose compute that benefits from higher FP32 throughput, the AMD Radeon Pro W6900X is the better pick. Its 22.23 TFLOPS FP32, 277.9 GPixel/s pixel rate, and 1.7% Vulkan win demonstrate clear graphics-oriented superiority. The W6900X also offers display outputs and a 226,821 Metal score, making it the only viable choice for Mac-based visual workloads. With an average score 3.7% higher than the A100 and a narrower loss in its weakest test, the W6900X emerges as the more balanced performer. Ultimately, the A100 wins for compute-heavy, headless server deployments, while the W6900X wins for graphics-centric workstations where display output and Vulkan efficiency matter.