AMD Instinct MI455X vs AMD Radeon PRO W7900 Comparison

Head-to-Head Benchmarks

The database does not contain any direct head-to-head benchmark results between the AMD Instinct MI455X and the AMD Radeon PRO W7900. The head-to-head benchmark array is empty, and the MI455X has no recorded benchmark scores, no average benchmark score, and no nearest rivals listed. Its percentile vs all GPUs is 50, which represents a median position among all recorded GPUs, but with zero actual measurements, this percentile is derived from its specification profile rather than observed performance.

The Radeon PRO W7900, by contrast, has two recorded benchmark results. In Geekbench OpenCL, it scores 84,379 points. In Geekbench Vulkan, it scores 137,070 points. Its average benchmark score across the recorded tests is 110,725 points, placing it in the 94th percentile of all GPUs in the database. The nearest rivals for the W7900 provide context for this score. The AMD Radeon Pro Vega II averages 109,617 points, which is 1% behind the W7900. The AMD Radeon Pro W6600X averages 107,342 points, 3.2% behind. The NVIDIA RTX A5500 Mobile averages 113,944 points, putting it 2.8% ahead of the W7900. The NVIDIA Tesla V100 SXM2 16 GB averages 114,395 points, which is 3.2% ahead. The W7900 therefore sits within a tight cluster of workstation GPUs, with all four nearest rivals within roughly 3.2% of its average score in either direction.

Because the MI455X has no benchmark entries, no direct comparison of measured performance is possible from the recorded data. The specification sheet, however, suggests a very different performance class. The MI455X lists FP32 throughput of 157.3 TFLOPS and FP16 throughput of 157.3 TFLOPS (1:1). The W7900 lists FP32 throughput of 61.32 TFLOPS and FP16 throughput of 61.32 TFLOPS (1:1). These figures indicate the MI455X is specified for roughly 2.57 times the raw FP32 compute of the W7900, though these are theoretical peak rates, not measured benchmark results. The texture rate follows the same pattern: the MI455X lists 2,457.6 GTexel/s versus 958.1 GTexel/s for the W7900. The pixel rate reverses strongly: the MI455X lists 0 MPixel/s due to having no ROPs, while the W7900 lists 479.0 GPixel/s from its 192 ROPs. The MI455X is a compute-oriented accelerator with no display or rasterization pipeline, while the W7900 is a full graphics card.

Memory capacity and bandwidth also diverge sharply. The MI455X carries 432 GB of HBM4 across a 24,576-bit bus, yielding 23.3 TB/s of bandwidth. The W7900 carries 48 GB of GDDR6 across a 384-bit bus, yielding 864.0 GB/s of bandwidth. The MI455X has 27 times the memory capacity and roughly 27 times the bandwidth by specification. The memory clock differs as well: 1900 MHz (7.6 Gbps effective) for the MI455X versus 2250 MHz (18 Gbps effective) for the W7900, though the much wider bus on the MI455X compensates.

The Verdict

The data supports a clear functional split. The AMD Instinct MI455X is an accelerator module with no display outputs, no ROPs, no graphics API support (DirectX, OpenGL, and Vulkan are all listed as N/A), and a 2300 W TDP. It is designed for compute workloads that scale with FP32/FP16 throughput, memory capacity, and memory bandwidth. The AMD Radeon PRO W7900 is a triple-slot workstation graphics card with 3x DisplayPort 2.1 and 1x mini-DisplayPort 2.1 outputs, DirectX 12 Ultimate (12_2), OpenGL 4.6, Vulkan 1.4, 96 ray accelerators, and a 295 W TDP. It is designed for graphics rendering, display output, and rasterization.

Who should pick which follows directly from these recorded characteristics. A user whose work requires rendering, display output, or graphics API support should select the W7900, as the MI455X offers no display connectivity and no graphics API compatibility. A user whose work requires maximum FP32 compute, very large memory capacity, or extremely high memory bandwidth should select the MI455X, as its specification sheet lists 157.3 TFLOPS FP32, 432 GB of HBM4, and 23.3 TB/s bandwidth. The W7900 has the only measured benchmark scores in the database, so any claim about real-world W7900 performance is grounded in Geekbench OpenCL and Vulkan results; the MI455X has no measured results to cite.

The power requirements reinforce this split. The MI455X lists a 2300 W TDP and a suggested PSU of 2700 W. The W7900 lists a 295 W TDP and a suggested PSU of 600 W. The MI455X also has no power connectors listed because it is an EAM Module, whereas the W7900 uses 2x 8-pin connectors. The physical form factors differ accordingly: the MI455X is described as an EAM Module with no dimensions recorded, while the W7900 measures 280 mm in length, 110 mm in height, and 51 mm in width.

Architecture Differences

The MI455X uses the CDNA 5.0 architecture on the MI450 256CU chip. The W7900 uses the RDNA 3.0 architecture on the Navi 31 chip, codenamed Plum Bonito. These are fundamentally different architecture families. CDNA is compute-focused, and the MI455X reflects that focus with 32,768 shading units, 1,024 texture mapping units, and zero ROPs. It has no ray accelerators listed and no tensor cores listed. The W7900 has 6,144 shading units, 384 texture mapping units, 192 ROPs, and 96 ray accelerators. The MI455X lists no RT cores, while the W7900 has dedicated ray acceleration hardware for graphics workloads.

The process nodes differ as well. The MI455X is built on a 2 nm process at TSMC, while the W7900 is built on a 5 nm process at TSMC. The transistor counts reflect the scale difference: the MI455X integrates 320,000 million transistors on a 2,990 mm² die, giving a transistor density of 107.0M per mm². The W7900 integrates 57,700 million transistors on a 529 mm² die, giving a transistor density of 109.1M per mm². The MI455X has over 5.5 times the transistor count of the W7900 and a die over 5.6 times larger, yet the density is nearly identical, indicating both chips use similar transistor packing per area despite the different process nodes.

The memory architectures are entirely different. The MI455X uses HBM4 with a 24,576-bit bus width. The W7900 uses GDDR6 with a 384-bit bus width. The MI455X has no display outputs because HBM4 stacks are integrated on-package for compute bandwidth, whereas the W7900's GDDR6 is paired with a full display controller. The MI455X lists its bus interface as PCIe 6.0 x16, while the W7900 uses PCIe 4.0 x16. The MI455X lists its slot width as EAM Module, which is a modular accelerator form factor, while the W7900 is a standard triple-slot PCIe card.

Specification Differences

The two cards differ across nearly every specification field. The MI455X has a base clock of 1000 MHz and a boost clock of 2400 MHz. The W7900 has a base clock of 1760 MHz and a boost clock of 2495 MHz. The W7900 has the higher base and boost clocks, but the MI455X compensates with far more shading units. The MI455X memory clock is 1900 MHz (7.6 Gbps effective), while the W7900 memory clock is 2250 MHz (18 Gbps effective). The W7900 runs its memory faster per pin, but the MI455X's 64 times wider bus (24,576 bit versus 384 bit) produces far higher total bandwidth.

The MI455X has 32,768 shading units versus 6,144 for the W7900, 1,024 TMUs versus 384, and 0 ROPs versus 192. The MI455X lists no ray accelerators, while the W7900 lists 96. The pixel rate is 0 MPixel/s for the MI455X versus 479.0 GPixel/s for the W7900. The texture rate is 2,457.6 GTexel/s for the MI455X versus 958.1 GTexel/s for the W7900. FP32 performance is 157.3 TFLOPS versus 61.32 TFLOPS. FP16 performance is 157.3 TFLOPS (1:1) versus 61.32 TFLOPS (1:1). Both maintain a 1:1 FP16 to FP32 ratio.

The TDP differs by 2,005 W: 2300 W for the MI455X versus 295 W for the W7900. The suggested PSU differs by 2,100 W: 2700 W versus 600 W. The MI455X has no power connectors listed because it is an EAM Module; the W7900 uses 2x 8-pin connectors. The W7900 has a production status of Active, while the MI455X has no production status listed. The release dates differ: the MI455X is dated 2026-07-22, while the W7900 is dated 2023-05-25. The W7900 has a launch MSRP of 3,999 USD; the MI455X has no launch MSRP listed. The W7900 supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. The MI455X lists N/A for all three APIs. The W7900 has display outputs: 3x DisplayPort 2.1 and 1x mini-DisplayPort 2.1. The MI455X has no outputs.

FAQ

Q: Which GPU has higher recorded benchmark scores?

A: Only the AMD Radeon PRO W7900 has recorded benchmark scores. It scores 84,379 in Geekbench OpenCL and 137,070 in Geekbench Vulkan, for an average of 110,725. The AMD Instinct MI455X has no benchmark entries in the database.

Q: How does the W7900 compare to its nearest rivals?

A: The W7900's average score of 110,725 is 1% above the AMD Radeon Pro Vega II (109,617), 3.2% above the AMD Radeon Pro W6600X (107,342), 2.8% below the NVIDIA RTX A5500 Mobile (113,944), and 3.2% below the NVIDIA Tesla V100 SXM2 16 GB (114,395).

Q: Which GPU has more memory?

A: The AMD Instinct MI455X has 432 GB of HBM4 memory, while the AMD Radeon PRO W7900 has 48 GB of GDDR6 memory. The MI455X also has a wider memory bus at 24,576 bit versus 384 bit, and higher bandwidth at 23.3 TB/s versus 864.0 GB/s.

Q: Can the MI455X output video?

A: No. The AMD Instinct MI455X lists "No outputs" for display outputs and lists N/A for DirectX, OpenGL, and Vulkan support. The AMD Radeon PRO W7900 has 3x DisplayPort 2.1 and 1x mini-DisplayPort 2.1 outputs.

Q: Which GPU has higher FP32 compute?

A: The AMD Instinct MI455X lists 157.3 TFLOPS FP32, while the AMD Radeon PRO W7900 lists 61.32 TFLOPS FP32. The MI455X is specified at roughly 2.57 times the FP32 throughput of the W7900.

Q: What are the power requirements for each GPU?

A: The AMD Instinct MI455X has a TDP of 2300 W and a suggested PSU of 2700 W. The AMD Radeon PRO W7900 has a TDP of 295 W and a suggested PSU of 600 W. The MI455X has no power connectors listed, while the W7900 uses 2x 8-pin connectors.

Where Each One Wins

The AMD Instinct MI455X wins on every recorded compute metric. It lists higher FP32 performance (157.3 TFLOPS versus 61.32 TFLOPS), higher FP16 performance (157.3 TFLOPS versus 61.32 TFLOPS), higher texture rate (2,457.6 GTexel/s versus 958.1 GTexel/s), more shading units (32,768 versus 6,144), more TMUs (1,024 versus 384), more memory (432 GB versus 48 GB), wider memory bus (24,576 bit versus 384 bit), higher memory bandwidth (23.3 TB/s versus 864.0 GB/s), and a larger transistor count (320,000 million versus 57,700 million). It also uses a newer process node (2 nm versus 5 nm) and a newer PCIe interface (PCIe 6.0 x16 versus PCIe 4.0 x16). These specifications point toward large-scale compute workloads such as AI training or high-performance computing, where raw throughput and memory capacity dominate.

The AMD Radeon PRO W7900 wins on every recorded graphics and display metric. It has 192 ROPs versus 0, a pixel rate of 479.0 GPixel/s versus 0 MPixel/s, 96 ray accelerators versus none listed, display outputs versus none, full graphics API support versus N/A across DirectX, OpenGL, and Vulkan, and a far lower TDP at 295 W versus 2300 W. It also has a smaller physical footprint at 280 mm length, 110 mm height, and 51 mm width, and it uses standard 2x 8-pin power connectors rather than an EAM Module form factor. The W7900 is the only one of the two with actual benchmark scores in the database, with its Geekbench Vulkan score of 137,070 significantly higher than its Geekbench OpenCL score of 84,379, indicating particularly strong Vulkan performance.

The data does not record a single workload where the two overlap. The MI455X is a compute accelerator with no graphics path, and the W7900 is a graphics workstation card with a compute path. The 1:1 FP16 to FP32 ratio on both cards means neither has a dedicated half-precision boost, so the MI455X's advantage in FP16 mirrors its FP32 advantage. The W7900's higher boost clock of 2495 MHz versus 2400 MHz is its only clock-speed advantage, but the MI455X's 32,768 shading units overwhelm that clock difference in aggregate throughput. The W7900's higher memory clock of 2250 MHz versus 1900 MHz is similarly outweighed by the MI455X's 64 times wider bus. In short, the MI455X is specified for compute density, and the W7900 is specified for graphics and display.