AMD Instinct MI100 vs AMD Radeon PRO W6800 Comparison

AMD’s Instinct MI100 and Radeon PRO W6800 are both 7 nm TSMC parts aimed at professional workloads, but they target very different corners of the market. The MI100 is a compute accelerator built for datacenter-scale number crunching, while the W6800 is a workstation card designed to drive displays and accelerate content creation. The data shows a clear split in capabilities, with the MI100 taking the lead in raw compute throughput and the W6800 offering a full feature set for graphics and rendering. Neither card is a universal winner; the right choice depends entirely on whether your priority is floating-point performance or visual output.

Head-to-Head Benchmarks

The only directly comparable benchmark in the data is Geekbench OpenCL, and it favors the MI100 decisively. The MI100 scores 139,035 points against the W6800’s 121,808 points, a 14.1% advantage. This is not a marginal gap; it represents a substantial lead in general-purpose compute workloads. For context, the MI100’s score places it 0.7% ahead of the NVIDIA Tesla V100 PCIe 16 GB and 0.9% ahead of the Tesla V100 SXM2 32 GB, meaning it edges out one of the most widely deployed accelerators in scientific computing. The W6800, meanwhile, sits just 0.1% behind the NVIDIA A10M and RTX 4000 Ada Generation, indicating it is squarely in the middle of the professional GPU pack for OpenCL tasks.

The MI100’s win is driven by its architecture, which prioritizes raw FP32 throughput over everything else. Its 23.07 TFLOPS FP32 figure is 29.4% higher than the W6800’s 17.83 TFLOPS, and that translates directly into the 14.1% benchmark lead. The W6800 does fight back in other metrics, but not in this test. The data shows only one head-to-head benchmark result, so the MI100 takes the sole win with a 1-0 record. There is no Vulkan or Metal comparison available, though the W6800 posts its own scores in those APIs—174,420 in Metal and 109,961 in Vulkan—which the MI100 cannot match because it has no display outputs and no graphics API support.

Architecture Differences

The two cards are built on fundamentally different architectures. The MI100 uses CDNA 1.0, AMD’s compute-only design, while the W6800 uses RDNA 2.0, the gaming-derived graphics architecture. This is the core of the divergence. CDNA 1.0 strips out all graphics-specific hardware to maximize compute density, while RDNA 2.0 retains the full graphics pipeline. The chip design reflects this: the MI100’s Arcturus die measures 750 mm², significantly larger than the W6800’s 520 mm² Navi 21. Interestingly, the W6800 packs more transistors—26,800 million versus 25,600 million—into that smaller die, resulting in a much higher transistor density of 51.5M per mm² versus 34.1M per mm².

The compute unit configuration tells the story of specialization. The MI100 has 7,680 shading units, exactly double the W6800’s 3,840. It also has 480 texture mapping units versus 240, but the W6800 counters with 96 ROPs against the MI100’s 64. The MI100’s advantage in shading units and TMUs is what drives its higher FP32 and FP16 throughput, but the W6800’s higher pixel rate—222.9 GPixel/s versus 96.13 GPixel/s—shows where the RDNA 2.0 architecture focuses its resources. The W6800 also includes 60 ray tracing cores, a feature entirely absent from the MI100, which has no RT cores, tensor cores, or any graphics-specific hardware.

Memory systems could not be more different. The MI100 uses 32 GB of HBM2 on a 4096-bit bus, delivering 1.23 TB/s of bandwidth. The W6800 has the same 32 GB capacity but uses GDDR6 on a 256-bit bus, yielding 512.0 GB/s. That is a 58.4% bandwidth deficit for the W6800, which will hurt in memory-bound compute tasks but is less critical for graphics workloads where cache hierarchies and compression matter more. The MI100’s memory clock is 1200 MHz (2.4 Gbps effective), while the W6800 runs at 2000 MHz (16 Gbps effective), but the massive bus width difference swamps the clock advantage.

FAQ

Q: Which card has higher FP32 performance?

A: The MI100 delivers 23.07 TFLOPS FP32, which is 29.4% higher than the W6800’s 17.83 TFLOPS. This directly contributes to its 14.1% lead in the Geekbench OpenCL test.

Q: Can the MI100 output video to a monitor?

A: No. The MI100 has no display outputs of any kind, whereas the W6800 provides six mini-DisplayPort 1.4a connections. The MI100 also lists no support for DirectX, OpenGL, or Vulkan, while the W6800 supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4.

Q: How do their memory bandwidths compare?

A: The MI100’s HBM2 memory delivers 1.23 TB/s over a 4096-bit bus, while the W6800’s GDDR6 memory provides 512.0 GB/s over a 256-bit bus. The MI100 has a 58.4% bandwidth advantage.

Q: What is the transistor density difference?

A: The W6800 packs 26,800 million transistors into a 520 mm² die, achieving 51.5M transistors per mm². The MI100 has 25,600 million transistors on a 750 mm² die, for a density of 34.1M per mm². The W6800 is significantly denser.

Q: Do both cards have ray tracing support?

A: No. The W6800 has 60 ray tracing cores, while the MI100 has none. The MI100 is purely a compute accelerator with no graphics pipeline.

Q: What is the power consumption difference?

A: The MI100 has a TDP of 300 W and requires a 700 W power supply, while the W6800 has a TDP of 250 W and a suggested 600 W PSU. The MI100 also needs two 8-pin power connectors, whereas the W6800 uses one 6-pin and one 8-pin.

Specification Differences

The two cards diverge on nearly every specification that matters. The MI100 uses the CDNA 1.0 architecture on the Arcturus chip, while the W6800 uses RDNA 2.0 on Navi 21. The MI100’s base clock is 1000 MHz with a 1502 MHz boost, while the W6800 runs much faster at 1575 MHz base and 2322 MHz boost—a 54.6% higher boost clock. The MI100 compensates with a larger die (750 mm² vs 520 mm²) but lower transistor density (34.1M/mm² vs 51.5M/mm²).

Memory configuration is a major differentiator: the MI100 uses 32 GB HBM2 on a 4096-bit bus with 1.23 TB/s bandwidth, while the W6800 uses 32 GB GDDR6 on a 256-bit bus with 512.0 GB/s. The MI100 has 7,680 shading units and 480 TMUs, versus 3,840 and 240 on the W6800. The W6800 has more ROPs (96 vs 64) and adds 60 ray tracing cores, which the MI100 lacks entirely. Pixel rate favors the W6800 at 222.9 GPixel/s versus 96.13 GPixel/s, but texture rate favors the MI100 at 721.0 GTexel/s versus 557.3 GTexel/s.

The MI100 is longer and shorter: both are 267 mm, but the MI100 is 111 mm tall versus 120 mm for the W6800. The W6800 is also 50 mm wide, a dimension not listed for the MI100. Power requirements differ, with the MI100 drawing 300 W and the W6800 drawing 250 W. The MI100 has no display outputs, while the W6800 has six mini-DisplayPort 1.4a. API support is entirely absent on the MI100, while the W6800 supports DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4. The MI100 also has a smaller average benchmark score of 139,035 versus the W6800’s 135,396, though this is skewed by the MI100 having only one benchmark result.

The Verdict

The data points to a simple conclusion: if you need raw compute throughput for scientific or datacenter workloads, the MI100 is the superior part. Its 14.1% OpenCL lead over the W6800, driven by double the shading units and 58.4% more memory bandwidth, makes it the clear choice for FP32-heavy tasks. Its 23.07 TFLOPS FP32 performance is among the best in its class, evidenced by its 96th percentile ranking among all GPUs and its narrow victory over the Tesla V100 series. The W6800 cannot match this in compute, and its 17.83 TFLOPS FP32 figure places it in a lower tier despite its 96th percentile ranking.

However, the W6800 is the only viable option for anyone who needs to connect a monitor. The MI100 has no display outputs and no graphics API support, making it useless for desktop work. The W6800’s six mini-DisplayPort 1.4a outputs, DirectX 12 Ultimate support, and 60 ray tracing cores make it a complete workstation solution for content creation, 3D rendering, and CAD work. Its higher pixel rate of 222.9 GPixel/s also indicates better rasterization throughput, which is essential for real-time viewport performance. The W6800 launched at 2,249 USD, while the MI100 has no listed launch MSRP, but the data does not support any price-based analysis.

Where Each One Wins

The MI100 wins in every scenario where compute throughput is the bottleneck. Its 1.23 TB/s memory bandwidth is critical for large dataset processing, such as AI training, scientific simulations, and financial modeling. The 14.1% OpenCL advantage over the W6800 is a direct measure of this capability. The MI100 also wins on texture rate (721.0 GTexel/s versus 557.3 GTexel/s) and FP16 performance (46.14 TFLOPS versus 35.67 TFLOPS), making it the better choice for mixed-precision workloads. Its 300 W TDP is higher, but the compute density justifies the power draw for server deployments.

The W6800 wins in every scenario that involves graphics output or interactive work. It is the only option with display outputs, so any workstation that requires a GUI must use it. Its 60 ray tracing cores enable hardware-accelerated ray tracing, which the MI100 cannot do at all. The W6800’s higher pixel rate (222.9 GPixel/s) and faster boost clock (2322 MHz versus 1502 MHz) make it better suited for viewport rendering and real-time visualization. Its API support for DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4 means it works with standard graphics software, whereas the MI100 is limited to compute APIs. The W6800 also has a lower TDP at 250 W and requires a smaller 600 W PSU, making it easier to integrate into a standard workstation chassis.