AMD Instinct MI355X vs AMD Radeon PRO W7800 Comparison

FAQ

Q: What are the core architectural differences between the AMD Instinct MI355X and the AMD Radeon PRO W7800?

A: The MI355X uses the CDNA 4.0 architecture built on TSMC's 3 nm process, while the W7800 uses RDNA 3.0 on a 5 nm process. The MI355X is a compute-focused accelerator with 16,384 shading units, while the W7800 has 4,480 shading units and includes 70 ray tracing cores.

Q: How do their memory subsystems compare?

A: The MI355X has 288 GB of HBM3e memory on an 8192-bit bus, delivering 8.19 TB/s of bandwidth. The W7800 has 32 GB of GDDR6 memory on a 256-bit bus with 576.0 GB/s bandwidth. The MI355X's bandwidth is over 14 times higher.

Q: Which card has higher FP32 compute throughput?

A: The MI355X delivers 78.64 TFLOPS of FP32 performance, compared to 45.25 TFLOPS for the W7800. The MI355X exceeds the W7800 by approximately 74% in this metric.

Q: What are their power requirements?

A: The MI355X has a TDP of 1400 W and requires a suggested 1800 W power supply, while the W7800 has a TDP of 260 W with a suggested 600 W power supply. The MI355X offers no power connectors as it uses an OAM Module slot format.

Q: What is the release timeline for these two products?

A: The AMD Radeon PRO W7800 was released on April 12, 2023, with a launch MSRP of 2,499 USD. The AMD Instinct MI355X was released on June 11, 2025.

Q: Are there any benchmark scores recorded for the MI355X?

A: The database contains no benchmark scores for the MI355X, and its average benchmark score is 0 with a percentile rank of 50. The W7800 has recorded scores of 154,366 in Geekbench OpenCL and 175,422 in Geekbench Vulkan, placing it in the 97th percentile of all GPUs.

Architecture Differences

The two accelerators diverge fundamentally in their design missions. The Instinct MI355X uses CDNA 4.0, an architecture focused on data center compute workloads, while the Radeon PRO W7800 uses RDNA 3.0, a graphics-first architecture with workstation features.

The manufacturing processes highlight the generational gap. The MI355X is fabricated on a 3 nm process at TSMC, packing 185,000 million transistors into a 2380 mm² die. The W7800 uses TSMC's 5 nm node with 57,700 million transistors on a 529 mm² die. Interestingly, the W7800 achieves a higher transistor density of 109.1 million per mm² compared to the MI355X's 77.7 million per mm², reflecting the different design priorities and the enormous scale of the MI355X's memory controllers and compute arrays.

Compute resources differ substantially. The MI355X fields 16,384 shading units and 1,024 texture mapping units but has 0 ROPs and a pixel rate of 0 MPixel/s, confirming it has no graphics output path. The W7800 includes 4,480 shading units, 280 TMUs, 128 ROPs, and 70 ray tracing cores, with a pixel rate of 323.2 GPixel/s. The W7800 also supports DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4, while the MI355X reports N/A for all graphics APIs, further cementing its role as a pure compute processor.

Memory architecture represents the starkest divide. The MI355X uses HBM3e with 288 GB capacity and an 8192-bit interface, producing 8.19 TB/s bandwidth. The W7800 uses GDDR6 with 32 GB capacity on a 256-bit bus, producing 576.0 GB/s. The MI355X's memory bandwidth is 14.2 times higher than the W7800's, which is crucial for large-scale AI training and inference workloads.

Clock behavior also differs. The W7800 runs at a base clock of 1895 MHz and boosts to 2525 MHz, while the MI355X has a lower base of 1000 MHz but boosts to 2400 MHz. The W7800's memory runs at 2250 MHz (18 Gbps effective) versus the MI355X's 2000 MHz (8 Gbps effective), though the MI355X's vastly wider bus overcomes the lower per-pin speed.

Head-to-Head Benchmarks

Direct head-to-head benchmark data is absent from the database for these two cards. However, the available metrics allow a quantitative comparison based on recorded specifications and the W7800's benchmark results.

In FP32 throughput, the MI355X delivers 78.64 TFLOPS against the W7800's 45.25 TFLOPS. The MI355X leads by 33.39 TFLOPS, a 74% advantage. For FP16 compute, the relationship shifts: the W7800 produces 90.50 TFLOPS at a 2:1 ratio, while the MI355X produces 78.64 TFLOPS at a 1:1 ratio. This means the W7800 actually leads in raw FP16 throughput by 15% in this configuration, though the MI355X's 1:1 ratio suggests its FP16 performance may be more consistent across workloads that require full precision at half-precision speeds.

Texture and pixel rates favor opposite cards. The MI355X achieves 2,457.6 GTexel/s, which is 3.5 times the W7800's 707.0 GTexel/s. The W7800 counters with 323.2 GPixel/s versus the MI355X's 0 MPixel/s, reflecting the MI355X's complete lack of a rasterization pipeline.

The W7800's benchmark scores provide context for its competitive position. Its Geekbench OpenCL score of 154,366 and Vulkan score of 175,422 yield an average of 164,894, placing it in the 97th percentile of all GPUs. The nearest rivals show tight competition: NVIDIA RTX A5500 scores 165,217 (0.2% ahead), NVIDIA RTX 4500 Ada Generation scores 166,094 (0.7% ahead), NVIDIA A100 PCIe 40 GB scores 162,504 (1.5% behind), and AMD Radeon Pro W6900X scores 168,574 (2.2% ahead). The W7800 sits within a narrow 4.4% band of these competitors, indicating that its benchmark performance is well established relative to the workstation market.

The MI355X has no recorded benchmarks, no rivals listed, and an average score of 0 with a 50th percentile ranking. Its performance can only be projected from specifications, not from measured results in the database.

Specification Differences

| Specification | AMD Instinct MI355X | AMD Radeon PRO W7800 |

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

| Architecture | CDNA 4.0 | RDNA 3.0 |

| Codename | None | Plum Bonito |

| Process Node | 3 nm | 5 nm |

| Transistors | 185,000 million | 57,700 million |

| Die Size | 2380 mm² | 529 mm² |

| Transistor Density | 77.7M / mm² | 109.1M / mm² |

| Base Clock | 1000 MHz | 1895 MHz |

| Boost Clock | 2400 MHz | 2525 MHz |

| Memory Size | 288 GB | 32 GB |

| Memory Type | HBM3e | GDDR6 |

| Memory Bus Width | 8192 bit | 256 bit |

| Memory Bandwidth | 8.19 TB/s | 576.0 GB/s |

| Shading Units | 16384 | 4480 |

| TMUs | 1024 | 280 |

| ROPs | 0 | 128 |

| Ray Tracing Cores | None | 70 |

| Pixel Rate | 0 MPixel/s | 323.2 GPixel/s |

| Texture Rate | 2,457.6 GTexel/s | 707.0 GTexel/s |

| FP32 | 78.64 TFLOPS | 45.25 TFLOPS |

| FP16 | 78.64 TFLOPS (1:1) | 90.50 TFLOPS (2:1) |

| TDP | 1400 W | 260 W |

| Slot Width | OAM Module | Dual-slot |

| Power Connectors | None | 2x 8-pin |

| Suggested PSU | 1800 W | 600 W |

| Bus Interface | PCIe 5.0 x16 | PCIe 4.0 x16 |

| Display Outputs | No outputs | 3x DisplayPort 2.1, 1x mini-DisplayPort 2.1 |

| DirectX Support | N/A | 12 Ultimate (12_2) |

| OpenGL Support | N/A | 4.6 |

| Vulkan Support | N/A | 1.4 |

| Dimensions | 102 mm x 165 mm | 280 mm x 110 mm x 40 mm |

| Release Date | June 11, 2025 | April 12, 2023 |

| Production Status | Not specified | Active |

| Launch MSRP | None | 2,499 USD |

Where Each One Wins

The MI355X wins decisively in compute throughput and memory capacity. Its 78.64 TFLOPS FP32 performance, 288 GB of HBM3e memory, and 8.19 TB/s bandwidth position it for large-scale data center workloads such as AI model training, scientific simulation, and high-performance computing. The 8192-bit memory bus and the 1:1 FP16 ratio indicate the card is engineered for sustained, precision-conscious compute tasks. Its PCIe 5.0 x16 interface doubles the interconnect bandwidth available to the W7800's PCIe 4.0 x16, which matters for data transfer in server environments.

The W7800 wins in graphics and workstation versatility. It provides display outputs, full graphics API support including DirectX 12 Ultimate and Vulkan 1.4, and 70 ray tracing cores. Its 323.2 GPixel/s pixel rate and 90.50 TFLOPS FP16 throughput make it relevant for visualization, rendering, and mixed precision workloads. The W7800's 260 W TDP and dual-slot form factor allow deployment in conventional workstation systems, whereas the MI355X requires an OAM module slot and an 1800 W power supply. The recorded benchmark scores confirm the W7800 operates competitively in its class, with an average score of 164,894 and a 97th percentile ranking among all GPUs.

The W7800 also wins on power efficiency based on the available data. It delivers 45.25 TFLOPS FP32 at 260 W, while the MI355X delivers 78.64 TFLOPS at 1400 W. Per watt, the W7800 achieves approximately 0.17 TFLOPS per watt versus the MI355X's 0.06 TFLOPS per watt, making the W7800 roughly three times more efficient in FP32 performance per watt.

The Verdict

The data presents two accelerators with fundamentally different purposes. The AMD Instinct MI355X is a data center compute accelerator with no graphics capabilities, no display outputs, and no recorded benchmarks in the database. Its specifications point to massive memory capacity, extreme bandwidth, and high FP32 throughput. The absence of benchmark data and the 50th percentile ranking mean its real-world performance remains unverified in this database. The 1400 W TDP and OAM Module form factor restrict it to specialized server infrastructure.

The AMD Radeon PRO W7800 is a workstation graphics card with verified performance. Its average benchmark score of 164,894 places it in the 97th percentile, with nearest rivals within a narrow 2.2% band. It offers display outputs, ray tracing, full graphics API support, and a conventional dual-slot form factor. The 260 W TDP and 600 W suggested power supply make it deployable in standard workstations.

For users with compute-centric workloads that require enormous memory capacity and bandwidth, the MI355X's specifications justify its existence despite the lack of measured benchmarks. For users needing graphics acceleration, workstation rendering, or general-purpose GPU compute with established performance, the W7800 has recorded results and a strong competitive position. The choice depends on whether the workload demands the MI355X's scale or the W7800's verified versatility.