AMD Instinct MI355X vs NVIDIA RTX PRO 4500 Blackwell Workstation Comparison

The Verdict

The AMD Instinct MI355X and NVIDIA RTX PRO 4500 Blackwell Workstation target entirely different segments of the GPU market. The MI355X is a massive compute accelerator built for dense server workloads, while the RTX PRO 4500 is a conventional workstation card with display outputs and moderate power requirements. The database shows no direct benchmark scores for either part, so the analysis rests on the recorded specifications and architectural data.

The MI355X suits environments where memory capacity and raw throughput dominate. Its 288 GB of HBM3e memory, 8.19 TB/s bandwidth, and 78.64 TFLOPS FP32 performance put it in a class above typical workstation parts. The 1400 W TDP and OAM module form factor require server infrastructure, not a desktop chassis. This card is for compute clusters, AI training nodes, or scientific computing racks.

The RTX PRO 4500 fits the traditional workstation role. It delivers 50.53 TFLOPS FP32, 32 GB of GDDR7 memory, 896.0 GB/s bandwidth, and four DisplayPort 2.1b outputs. Its 200 W TDP and dual-slot design allow installation in standard workstations. The card supports DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4, making it suitable for professional graphics applications alongside compute workloads.

Buyers should pick the MI355X only if they have the power delivery and cooling infrastructure for a 1400 W part with an 1800 W suggested PSU. The RTX PRO 4500 is the practical choice for desktop workstations, rendering, and any workload requiring display connectivity. The data shows no overlap in their intended use cases.

FAQ

Q: Which card has more memory bandwidth?

A: The AMD Instinct MI355X delivers 8.19 TB/s from its 8192-bit HBM3e interface. The NVIDIA RTX PRO 4500 provides 896.0 GB/s from a 256-bit GDDR7 bus. The MI355X bandwidth is roughly nine times higher.

Q: Can the MI355X output to displays?

A: No. The MI355X has no display outputs. The RTX PRO 4500 has four DisplayPort 2.1b outputs.

Q: What is the power consumption difference?

A: The MI355X has a 1400 W TDP with an 1800 W suggested PSU. The RTX PRO 4500 has a 200 W TDP with a 550 W suggested PSU. The AMD part consumes seven times the power of the NVIDIA card.

Q: Which card supports more graphics APIs?

A: The RTX PRO 4500 supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. The MI355X lists no API support in the database, showing N/A for DirectX, OpenGL, and Vulkan.

Q: How do their memory sizes compare?

A: The MI355X has 288 GB of HBM3e memory. The RTX PRO 4500 has 32 GB of GDDR7 memory. The AMD card has nine times the memory capacity.

Q: Which card was released earlier?

A: The RTX PRO 4500 released on 2025-03-17. The MI355X released on 2025-06-11, roughly three months later.

Architecture Differences

The two cards come from different architectural lineages. The MI355X uses CDNA 4.0 architecture built on a 3 nm process from TSMC. The chip, designated MI350 256CU, contains 185,000 million transistors on a 2380 mm² die. The transistor density measures 77.7M per mm². This is a compute-oriented design with no display pipeline.

The RTX PRO 4500 uses Blackwell 2.0 architecture on a 5 nm TSMC process. The GB203 chip contains 45,600 million transistors on a 378 mm² die, yielding a transistor density of 120.6M per mm². Blackwell 2.0 includes dedicated ray tracing cores and tensor cores, features absent from the MI355X specification.

The MI355X has 16,384 shading units, 1,024 texture mapping units, and no ROPs listed. Its pixel rate is recorded as 0 MPixel/s. The texture rate reaches 2,457.6 GTexel/s. The RTX PRO 4500 has 10,496 shading units, 328 TMUs, and 112 ROPs. It delivers 269.6 GPixel/s pixel rate and 789.5 GTexel/s texture rate.

The NVIDIA card includes 82 ray tracing cores and 328 tensor cores. The AMD card lists no equivalent hardware. The MI355X supports FP16 at a 1:1 ratio with FP32, both at 78.64 TFLOPS. The RTX PRO 4500 also supports FP16 at 1:1, with both at 50.53 TFLOPS.

The MI355X uses an OAM module form factor with no power connectors listed. The RTX PRO 4500 uses a dual-slot design with a single 16-pin power connector. Both cards use PCIe 5.0 x16 as their bus interface.

Specification Differences

The memory subsystem differs fundamentally. The MI355X uses HBM3e with 288 GB capacity, an 8192-bit bus, and 8.19 TB/s bandwidth. Memory clock is 2000 MHz with 8 Gbps effective. The RTX PRO 4500 uses GDDR7 with 32 GB capacity, a 256-bit bus, and 896.0 GB/s bandwidth. Memory clock is 1750 MHz with 28 Gbps effective.

Clock speeds show the NVIDIA card running higher. The RTX PRO 4500 has a 1635 MHz base clock and 2407 MHz boost. The MI355X has a 1000 MHz base and 2400 MHz boost. Despite lower clocks, the AMD part achieves higher FP32 throughput due to its larger shader array.

Physical dimensions differ substantially. The MI355X measures 102 mm in length and 165 mm in width, with no height recorded. The RTX PRO 4500 measures 267 mm in length, 111 mm in height, and 40 mm in width. The NVIDIA card is a standard dual-slot workstation card, while the AMD part uses a server-oriented OAM module.

Power requirements are the most striking difference. The MI355X has a 1400 W TDP and suggests an 1800 W PSU. The RTX PRO 4500 has a 200 W TDP and suggests a 550 W PSU. The AMD card requires seven times the power budget.

The production status differs. The RTX PRO 4500 is listed as Active. The MI355X has no production status recorded. The predecessor of the RTX PRO 4500 is Workstation Ada. The predecessor of the MI355X is Radeon Instinct. Neither card has a successor listed.

The MI355X has no launch MSRP recorded, and the RTX PRO 4500 also has no launch MSRP recorded. Both cards sit at the 50th percentile versus all GPUs in the database.

Head-to-Head Benchmarks

The database contains no direct head-to-head benchmark results between these two cards. Both have empty benchmark arrays and zero average benchmark scores. The wins count for each card is zero. This means the comparison must rely on specification-derived performance indicators.

The FP32 compute comparison shows the MI355X ahead. It delivers 78.64 TFLOPS versus 50.53 TFLOPS for the RTX PRO 4500. That represents a 55.6% advantage for the AMD card. FP16 performance follows the same pattern, with the MI355X at 78.64 TFLOPS and the RTX PRO 4500 at 50.53 TFLOPS.

Memory bandwidth heavily favors the MI355X. Its 8.19 TB/s is approximately 9.1 times the 896.0 GB/s of the RTX PRO 4500. Memory capacity also favors AMD by a factor of nine, 288 GB versus 32 GB. These differences matter for large datasets that exceed the NVIDIA card's capacity.

Texture throughput favors the MI355X. It reaches 2,457.6 GTexel/s against 789.5 GTexel/s for the RTX PRO 4500. The AMD card has more than three times the texture fill rate. Pixel throughput favors the RTX PRO 4500, which delivers 269.6 GPixel/s while the MI355X records 0 MPixel/s.

The RTX PRO 4500 wins on clock speeds. Its 1635 MHz base clock is 63.5% higher than the MI355X's 1000 MHz. The boost clocks are close, 2407 MHz versus 2400 MHz. The NVIDIA card also has a much higher transistor density at 120.6M per mm² against 77.7M per mm².

Power efficiency favors NVIDIA by a wide margin. The RTX PRO 4500 delivers 50.53 TFLOPS FP32 at 200 W TDP, while the MI355X delivers 78.64 TFLOPS at 1400 W. Per watt, the NVIDIA card produces 0.25 TFLOPS per watt, while the AMD card produces 0.056 TFLOPS per watt. The NVIDIA card is roughly 4.5 times more power efficient in raw FP32 terms.

The RTX PRO 4500 supports the full range of workstation APIs. DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4 are all listed. The MI355X shows N/A for all three, indicating no graphics API support. This makes the NVIDIA card the only option for applications requiring these interfaces.

Where Each One Wins

The MI355X dominates in compute density. It offers 78.64 TFLOPS FP32 and FP16, 288 GB of HBM3e memory, and 8.19 TB/s bandwidth. These specifications suit large-scale AI training, scientific simulations, and data processing workloads where memory capacity and throughput are critical. The 8192-bit memory bus and HBM3e technology allow it to feed its 16,384 shading units without bottleneck. The 2,457.6 GTexel/s texture rate indicates strong fill performance for compute-heavy operations.

The RTX PRO 4500 wins in every workstation-oriented category. It has display outputs, API support, ray tracing cores, tensor cores, and a manageable 200 W power envelope. The 269.6 GPixel/s pixel rate and 112 ROPs make it suitable for rendering and graphics tasks. The 82 ray tracing cores and 328 tensor cores provide hardware acceleration for workloads the MI355X cannot handle. Its 4x DisplayPort 2.1b outputs enable multi-monitor setups.

Power delivery separates the use cases decisively. The MI355X requires server infrastructure with an 1800 W suggested PSU. The RTX PRO 4500 fits into a standard workstation with a 550 W suggested PSU. The NVIDIA card's 267 mm length and dual-slot width are conventional dimensions. The AMD card's OAM module format is not designed for desktop installation.

The production status further clarifies the picture. The RTX PRO 4500 is Active, meaning it is available for purchase. The MI355X has no production status recorded, suggesting limited availability or a different distribution model. The RTX PRO 4500 also has a broader software ecosystem due to its API support.

Applications requiring high memory capacity with compute acceleration should use the MI355X. Applications requiring display output, graphics APIs, or ray tracing should use the RTX PRO 4500. The data shows no scenario where both cards compete for the same workload. The MI355X is a server accelerator with no graphics functionality. The RTX PRO 4500 is a workstation GPU with balanced compute and graphics capabilities.

For builders assembling a new workstation, the RTX PRO 4500 is the only viable option between these two. It offers display connectivity, standard form factor, and reasonable power requirements. The MI355X demands substantial infrastructure investment in power delivery and cooling, with the 1400 W TDP as the primary constraint. The 1800 W suggested PSU indicates a server-class power supply requirement.

For organizations running compute clusters, the MI355X provides superior raw performance metrics. Its 288 GB memory capacity can hold models and datasets that would exceed the 32 GB limit of the RTX PRO 4500. The 8.19 TB/s bandwidth enables faster data movement for memory-bound workloads. The 78.64 TFLOPS FP32 performance represents significant compute throughput.

The absence of benchmark scores in the database means real-world performance comparisons remain unknown. The specification analysis provides the available evidence. The MI355X and RTX PRO 4500 serve different markets, and the data supports that conclusion clearly.