AMD Radeon Pro Duo vs AMD Radeon PRO W6400 Comparison

# The Verdict

The AMD Radeon PRO W6400 and AMD Radeon Pro Duo are both end-of-life workstation cards, but they serve completely different buyers. The data shows the Radeon Pro Duo wins the only head-to-head benchmark available, scoring 35,860 in Geekbench OpenCL against the W6400's 35,027 — a 2.3% margin. However, the W6400 counters with a second benchmark result, 39,286 in Geekbench Vulkan, which the Pro Duo has no recorded score for. This means the Pro Duo is the better choice for OpenCL-centric workloads, while the W6400 is the only one of the two with proven Vulkan performance.

The Radeon Pro Duo's 80th percentile ranking places it alongside the NVIDIA Quadro GV100 (1% behind) and the NVIDIA GeForce RTX 5070 Ti Mobile (1.2% behind), showing it still competes with recent mid-range hardware. The W6400 also sits at the 80th percentile, with its average score of 37,157 putting it 0.9% behind the AMD Radeon RX Vega 56 and 1.3% behind both the NVIDIA Tesla P4 and the NVIDIA GeForce RTX 4070. Both cards are essentially tied in overall positioning, but the Pro Duo's raw FP32 throughput of 8.192 TFLOPS is more than double the W6400's 3.565 TFLOPS, making it the obvious pick for compute-heavy tasks.

Choose the W6400 if you need modern API support (DirectX 12 Ultimate, Vulkan 1.4), lower power draw, and PCIe 4.0 connectivity. Choose the Pro Duo if you need raw compute power, massive memory bandwidth, and don't mind a dual-slot card with three 8-pin power connectors. The Pro Duo launched at an MSRP of 1,499 USD, a price point that reflects its dual-GPU-class compute capability.

# Architecture Differences

The two cards come from entirely different eras of AMD's GPU design. The W6400 uses the Navi 24 chip built on RDNA 2.0 architecture, manufactured on TSMC's 6 nm process. It packs 5,400 million transistors into a 107 mm² die, achieving a transistor density of 50.5M per mm². The Pro Duo, codenamed Capsaicin, uses GCN 3.0 architecture on a 28 nm process, with 8,900 million transistors spread across a massive 596 mm² die — a transistor density of just 14.9M per mm². The density difference is stark: the W6400 crams roughly 3.4 times more transistors per square millimeter.

Memory architecture is where the two diverge most dramatically. The W6400 uses 4 GB of GDDR6 on a 64-bit bus, yielding 128.0 GB/s of bandwidth. The Pro Duo also has 4 GB, but it's HBM on a 4096-bit bus, delivering 512.0 GB/s — exactly four times the bandwidth. The Pro Duo's memory clock is listed at 500 MHz (1000 Mbps effective), while the W6400 runs at 2000 MHz (16 Gbps effective). The W6400 compensates for its narrow bus with much higher clock speeds, but the Pro Duo's sheer bus width wins on total throughput.

Compute resources tell a similar story. The Pro Duo has 4096 shading units, 256 TMUs, and 64 ROPs, versus the W6400's 768 shading units, 48 TMUs, and 32 ROPs. The Pro Duo also has 12 RT cores on the W6400 — a feature the older GCN architecture lacks entirely. The W6400 supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4, while the Pro Duo is limited to DirectX 12 (12_0), OpenGL 4.6, and Vulkan 1.2.170. The W6400's FP16 performance of 7.130 TFLOPS comes via a 2:1 ratio, whereas the Pro Duo's FP16 equals its FP32 at 8.192 TFLOPS (1:1).

Power and physical requirements differ enormously. The W6400 sips 50 W, requires no power connectors, and is single-slot with a suggested PSU of 250 W. The Pro Duo draws 350 W, needs three 8-pin connectors, is dual-slot, and demands a 750 W PSU. The Pro Duo measures 277 mm in length and 111 mm in height; the W6400's dimensions are not listed. The Pro Duo's display outputs include 1x HDMI 1.4a and 3x DisplayPort 1.2, while the W6400 offers 2x DisplayPort 1.4a.

# Head-to-Head Benchmarks

Only one benchmark directly pits these two cards against each other: Geekbench OpenCL. The Radeon Pro Duo scores 35,860, beating the Radeon PRO W6400's 35,027 by 2.3%. This is a narrow margin, but it's consistent with the Pro Duo's raw compute advantage. In terms of pure FP32 throughput, the Pro Duo's 8.192 TFLOPS is 130% higher than the W6400's 3.565 TFLOPS, yet the benchmark gap is only 2.3%. This suggests the W6400's modern architecture extracts far more efficiency from each FLOP, or that the OpenCL workload doesn't scale perfectly with the Pro Duo's dual-GPU design.

The W6400 has a second benchmark result: 39,286 in Geekbench Vulkan. This score is 12.2% higher than its own OpenCL result, and it's 9.6% higher than the Pro Duo's OpenCL score. Since the Pro Duo has no Vulkan benchmark recorded, the W6400 is the only card of the two with verified Vulkan performance. For any Vulkan-based workload, the W6400 is the only option with data to back it up.

Looking at rival comparisons, the Pro Duo's average score of 35,860 places it 1% ahead of the NVIDIA Quadro GV100 and 1.2% ahead of the NVIDIA GeForce RTX 5070 Ti Mobile, while trailing the NVIDIA T1000 by 1.2% and the AMD Radeon RX 5300M by 1.8%. The W6400's average of 37,157 is 1.7% ahead of the NVIDIA GeForce GTX TITAN X, but 0.9% behind the AMD Radeon RX Vega 56 and 1.3% behind both the NVIDIA Tesla P4 and the NVIDIA GeForce RTX 4070. Both cards occupy the same performance tier, trading places with different rivals.

# FAQ

Q: Which card wins the only direct benchmark comparison?

A: The AMD Radeon Pro Duo wins Geekbench OpenCL with a score of 35,860 versus the W6400's 35,027, a 2.3% margin.

Q: Does the W6400 have any benchmark advantage?

A: Yes. The W6400 scores 39,286 in Geekbench Vulkan, a test the Pro Duo has no recorded result for. This gives the W6400 a verified Vulkan capability the Pro Duo lacks.

Q: How do their memory bandwidths compare?

A: The Pro Duo's HBM memory on a 4096-bit bus delivers 512.0 GB/s, exactly four times the W6400's 128.0 GB/s from GDDR6 on a 64-bit bus.

Q: What are the power requirements for each card?

A: The W6400 has a 50 W TDP with no power connectors and a 250 W suggested PSU. The Pro Duo has a 350 W TDP, requires three 8-pin connectors, and needs a 750 W suggested PSU.

Q: Do both cards support the same DirectX version?

A: No. The W6400 supports DirectX 12 Ultimate (12_2), while the Pro Duo is limited to DirectX 12 (12_0).

Q: Which card has ray tracing hardware?

A: The W6400 includes 12 RT cores. The Pro Duo has no RT cores listed.

# Where Each One Wins

The Radeon Pro Duo wins in raw compute throughput. Its 8.192 TFLOPS FP32 performance is more than double the W6400's 3.565 TFLOPS, and its 8.192 TFLOPS FP16 at a 1:1 ratio matches its FP32 output. The Pro Duo's 512.0 GB/s memory bandwidth is four times the W6400's, which matters for large datasets that exceed the 64-bit bus's capabilities. The Pro Duo also has more texture units (256 vs 48) and more ROPs (64 vs 32), giving it higher texture fill rate at 256.0 GTexel/s versus 111.4 GTexel/s. Its 64.00 GPixel/s pixel rate is lower than the W6400's 74.27 GPixel/s, but the Pro Duo compensates with sheer shading power. The Pro Duo wins OpenCL workloads, as shown by its direct benchmark victory.

The W6400 wins on efficiency and modern features. Its 50 W TDP is one-seventh of the Pro Duo's 350 W, and it needs no power connectors versus three 8-pin connectors. The 6 nm process node versus 28 nm means dramatically better transistor density (50.5M/mm² vs 14.9M/mm²), and the W6400's PCIe 4.0 x4 interface is newer than the Pro Duo's PCIe 3.0 x16. The W6400 supports DirectX 12 Ultimate and Vulkan 1.4, while the Pro Duo maxes out at DirectX 12 (12_0) and Vulkan 1.2.170. The W6400's 2x DisplayPort 1.4a outputs are newer than the Pro Duo's 1x HDMI 1.4a and 3x DisplayPort 1.2. The W6400's Vulkan score of 39,286 is the highest single benchmark result between the two cards, making it the pick for Vulkan-based applications.

Use the Pro Duo for OpenCL compute tasks, FP32-heavy simulations, or workloads that benefit from 512.0 GB/s bandwidth. Use the W6400 for Vulkan rendering, modern API support, low-power builds, or systems with limited PSU headroom. The Pro Duo's 1,499 USD launch MSRP reflects its workstation-class compute positioning, while the W6400's lower power and newer architecture make it a more flexible option for current software environments.

# Specification Differences

| Specification | AMD Radeon PRO W6400 | AMD Radeon Pro Duo |

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

| Chip | Navi 24 | Capsaicin |

| Architecture | RDNA 2.0 | GCN 3.0 |

| Process Node | 6 nm | 28 nm |

| Transistors | 5,400 million | 8,900 million |

| Die Size | 107 mm² | 596 mm² |

| Transistor Density | 50.5M / mm² | 14.9M / mm² |

| Base Clock | 2039 MHz | Not listed |

| Boost Clock | 2321 MHz | Not listed |

| Memory Clock | 2000 MHz (16 Gbps effective) | 500 MHz (1000 Mbps effective) |

| Memory Type | GDDR6 | HBM |

| Bus Width | 64 bit | 4096 bit |

| Bandwidth | 128.0 GB/s | 512.0 GB/s |

| Shading Units | 768 | 4096 |

| TMUs | 48 | 256 |

| ROPs | 32 | 64 |

| RT Cores | 12 | None |

| Pixel Rate | 74.27 GPixel/s | 64.00 GPixel/s |

| Texture Rate | 111.4 GTexel/s | 256.0 GTexel/s |

| FP32 | 3.565 TFLOPS | 8.192 TFLOPS |

| FP16 | 7.130 TFLOPS (2:1) | 8.192 TFLOPS (1:1) |

| TDP | 50 W | 350 W |

| Slot Width | Single-slot | Dual-slot |

| Power Connectors | None | 3x 8-pin |

| Suggested PSU | 250 W | 750 W |

| Bus Interface | PCIe 4.0 x4 | PCIe 3.0 x16 |

| Display Outputs | 2x DisplayPort 1.4a | 1x HDMI 1.4a, 3x DisplayPort 1.2 |

| DirectX | 12 Ultimate (12_2) | 12 (12_0) |

| Vulkan | 1.4 | 1.2.170 |

| Dimensions | Not listed | 277 mm length, 111 mm height |

| Release Date | 2022-01-18 | 2016-04-25 |

| Predecessor | Radeon Pro Vega | FirePro GCN |

| Successor | None | Radeon Pro Polaris |

| Launch MSRP | Not listed | 1,499 USD |