AMD Radeon Instinct MI25 vs AMD Radeon Pro W6800X Duo Comparison

Where Each One Wins

The benchmark data paints a clear picture of two very different compute-focused accelerators. The AMD Radeon Pro W6800X Duo and the AMD Radeon Instinct MI25 are not direct contemporaries, and the recorded measurements reflect a significant generational gap. The W6800X Duo takes the only head-to-head benchmark victory, but the MI25 still holds its own in specific contexts based on its architecture and feature set.

In the single available head-to-head test, Geekbench OpenCL, the W6800X Duo wins decisively. Its score of 124,335 dwarfs the MI25's 68,562, a delta of 81.3%. This is the only benchmark where both cards were tested under identical conditions, so it forms the backbone of any direct comparison. The W6800X Duo also has additional benchmark results in Metal and Vulkan, with scores of 157,365 and 125,622 respectively, which the MI25 lacks entirely. This means the W6800X Duo is the only one of the two that can be evaluated across multiple modern API workloads.

However, the MI25 is not without its own advantages. It uses HBM2 memory with a 2048-bit bus, which is a different memory architecture than the W6800X Duo's GDDR6 on a 256-bit bus. While the bandwidth figures are close, 436.2 GB/s for the MI25 versus 512.0 GB/s for the W6800X Duo, the MI25's memory configuration is historically associated with different compute workloads. The MI25 also has more shading units (4096 versus 3840) and more texture mapping units (256 versus 240), though it falls behind in ROPs (64 versus 96).

The percentile rankings place the W6800X Duo at the 96th percentile of all GPUs, while the MI25 sits at the 90th. This means the W6800X Duo outperforms a larger fraction of the database's tracked graphics cards. The average benchmark score for the W6800X Duo is 135,774, nearly double the MI25's 68,562. The W6800X Duo also has a 400 W TDP and requires an 800 W suggested PSU, while the MI25 draws 300 W and suggests a 700 W PSU, making the MI25 the more power-efficient option per watt of compute in a raw sense, though the W6800X Duo delivers far more absolute performance.

The Verdict

The data suggests that these two cards serve entirely different purposes, and the choice between them is dictated by workload and platform compatibility. The AMD Radeon Pro W6800X Duo is the clear performance winner in every measurable category. Its Geekbench OpenCL score is 81.3% higher, its average benchmark score is 135,774 versus 68,562, and it supports modern APIs like DirectX 12 Ultimate (12_2) and Vulkan 1.4. It also has display outputs (1x HDMI 2.1 and 4x Thunderbolt), making it usable for visualization tasks, not just compute.

The AMD Radeon Instinct MI25, on the other hand, is a compute-only accelerator with no display outputs. Its GCN 5.0 architecture and 14 nm process node are older, but it still achieves a respectable 90th percentile ranking. The MI25's 16 GB of HBM2 memory on a 2048-bit bus may be preferable in certain legacy compute environments that were optimized for this memory type. Its 300 W TDP and dual-slot form factor also make it easier to integrate into existing server infrastructure compared to the W6800X Duo's quad-slot design.

For anyone prioritizing raw compute throughput, modern API support, and the ability to drive displays, the W6800X Duo is the only rational choice. For environments that specifically require a power-efficient, compute-only accelerator with HBM2 memory and a PCIe 3.0 x16 interface, the MI25 remains a viable option, especially given that both cards are end-of-life products. The W6800X Duo was released on 2021-08-02, while the MI25 dates to 2017-06-26, so the former represents a much later design point.

Head-to-Head Benchmarks

The only direct comparison available in the database is the Geekbench OpenCL test. The W6800X Duo scored 124,335, while the MI25 scored 68,562. This gives the W6800X Duo an 81.3% advantage. This is a massive gap that cannot be explained by clock speeds alone. The W6800X Duo has a base clock of 1800 MHz and a boost of 1967 MHz, compared to the MI25's 1400 MHz base and 1500 MHz boost. The W6800X Duo's higher clocks, combined with its newer RDNA 2.0 architecture, deliver nearly double the FP32 throughput: 15.11 TFLOPS versus 12.29 TFLOPS.

The FP16 figures follow the same pattern, with the W6800X Duo at 30.21 TFLOPS (2:1) and the MI25 at 24.58 TFLOPS (2:1). In terms of pixel and texture rates, the W6800X Duo again leads, with 188.8 GPixel/s and 472.1 GTexel/s, versus the MI25's 96.00 GPixel/s and 384.0 GTexel/s. The W6800X Duo's texture rate is 22.9% higher, and its pixel rate is 96.7% higher, which aligns with the OpenCL score delta.

Looking at the nearest rivals in the database provides additional context. The W6800X Duo's average score of 135,774 places it just 0.3% ahead of the AMD Radeon PRO W6800 (135,396), 0.4% ahead of the NVIDIA A10M (135,230), and 0.4% ahead of the NVIDIA RTX 4000 Ada Generation (135,218). It trails the AMD Radeon PRO V620 (136,472) by 0.5%. This means the W6800X Duo is essentially tied with a cluster of high-end workstation cards, all within a 1% band.

The MI25's average score of 68,562 places it 0.4% behind the Intel Arc A770 (68,809), 0.6% behind the NVIDIA CMP 90HX (69,000), 1.9% behind the AMD Radeon Pro WX 8200 (69,870), and 2% behind the NVIDIA Quadro P6000 (69,986). The MI25 is at the bottom of this rival group, but the deltas are small, indicating that it still competes with much newer cards in raw OpenCL compute.

FAQ

Q: Which card has a higher Geekbench OpenCL score?

A: The AMD Radeon Pro W6800X Duo scores 124,335, which is 81.3% higher than the AMD Radeon Instinct MI25's score of 68,562.

Q: Do both cards support the same DirectX version?

A: No. The W6800X Duo supports DirectX 12 Ultimate (12_2), while the MI25 supports DirectX 12 (12_1).

Q: Which card has more memory bandwidth?

A: The W6800X Duo has 512.0 GB/s of bandwidth, while the MI25 has 436.2 GB/s. The W6800X Duo also has 32 GB of memory versus the MI25's 16 GB.

Q: Are both cards still in production?

A: No. Both are listed as end-of-life products.

Q: Does the MI25 have any display outputs?

A: No, the MI25 has no outputs. The W6800X Duo has 1x HDMI 2.1 and 4x Thunderbolt outputs.

Q: Which card requires a higher suggested power supply?

A: The W6800X Duo suggests an 800 W PSU, while the MI25 suggests a 700 W PSU. The W6800X Duo also has a 400 W TDP versus the MI25's 300 W TDP.

Architecture Differences

The two cards are built on fundamentally different architectures. The W6800X Duo uses the Navi 21 chip with RDNA 2.0 architecture, fabricated on a 7 nm process at TSMC. The MI25 uses the Vega 10 chip with GCN 5.0 architecture, fabricated on a 14 nm process at GlobalFoundries. This process node difference is significant: 7 nm versus 14 nm. The W6800X Duo packs 26,800 million transistors on a 520 mm² die, giving a transistor density of 51.5M per mm². The MI25 has 12,500 million transistors on a 495 mm² die, with a density of 25.3M per mm². The W6800X Duo has more than double the transistor count and more than double the density.

The W6800X Duo includes 60 ray tracing cores, which the MI25 lacks entirely. This is a major architectural divergence, as ray tracing is a feature of RDNA 2.0. The MI25 has no tensor cores, and neither does the W6800X Duo. The shading unit counts are close, with the MI25 having 4096 and the W6800X Duo having 3840, but the newer architecture of the W6800X Duo extracts more performance per shader. The W6800X Duo also supports Vulkan 1.4, while the MI25 supports Vulkan 1.3.

The memory subsystems are completely different. The W6800X Duo uses 32 GB of GDDR6 on a 256-bit bus, while the MI25 uses 16 GB of HBM2 on a 2048-bit bus. The W6800X Duo's memory clock is 2000 MHz (16 Gbps effective), while the MI25's is 852 MHz (1704 Mbps effective). Despite the much wider bus on the MI25, the W6800X Duo still achieves higher bandwidth. The W6800X Duo's power connector configuration is not specified, while the MI25 uses 2x 8-pin connectors.

Specification Differences

The following specifications differ between the two cards:

• Chip: Navi 21 (W6800X Duo) versus Vega 10 (MI25)
• Architecture: RDNA 2.0 versus GCN 5.0
• Process Node: 7 nm versus 14 nm
• Foundry: TSMC versus GlobalFoundries
• Transistors: 26,800 million versus 12,500 million
• Die Size: 520 mm² versus 495 mm²
• Transistor Density: 51.5M / mm² versus 25.3M / mm²
• Base Clock: 1800 MHz versus 1400 MHz
• Boost Clock: 1967 MHz versus 1500 MHz
• Memory Clock: 2000 MHz (16 Gbps effective) versus 852 MHz (1704 Mbps effective)
• Memory Size: 32 GB versus 16 GB
• Memory Type: GDDR6 versus HBM2
• Memory Bus Width: 256 bit versus 2048 bit
• Memory Bandwidth: 512.0 GB/s versus 436.2 GB/s
• Shading Units: 3840 versus 4096
• TMUs: 240 versus 256
• ROPs: 96 versus 64
• Ray Tracing Cores: 60 versus none
• Pixel Rate: 188.8 GPixel/s versus 96.00 GPixel/s
• Texture Rate: 472.1 GTexel/s versus 384.0 GTexel/s
• FP32 Performance: 15.11 TFLOPS versus 12.29 TFLOPS
• FP16 Performance: 30.21 TFLOPS versus 24.58 TFLOPS
• TDP: 400 W versus 300 W
• Slot Width: Quad-slot versus Dual-slot
• Power Connectors: Not specified versus 2x 8-pin
• Suggested PSU: 800 W versus 700 W
• Bus Interface: Apple MPX versus PCIe 3.0 x16
• Display Outputs: 1x HDMI 2.1, 4x Thunderbolt versus no outputs
• DirectX Support: 12 Ultimate (12_2) versus 12 (12_1)
• Vulkan Support: 1.4 versus 1.3
• Dimensions: 267 mm length, 120 mm height versus 267 mm length, 111 mm height
• Release Date: 2021-08-02 versus 2017-06-26
• Predecessor: None versus FirePro Data Center
• Launch MSRP: 4,999 USD versus not specified