AMD Instinct MI455X vs NVIDIA RTX PRO 6000 Blackwell Comparison

FAQ

Q: What are the two cards compared in this database entry?

A: The AMD Instinct MI455X and the NVIDIA RTX PRO 6000 Blackwell. The AMD card is built for compute-oriented Instinct workloads, while the NVIDIA card is a workstation-oriented Blackwell PRO product.

Q: Which card has more memory?

A: The AMD Instinct MI455X has 432 GB of HBM4 memory, while the NVIDIA RTX PRO 6000 Blackwell has 96 GB of GDDR7 memory.

Q: Which card has a higher boost clock?

A: The NVIDIA RTX PRO 6000 Blackwell has a boost clock of 2617 MHz, which is higher than the AMD Instinct MI455X's boost clock of 2400 MHz.

Q: Do both cards support standard graphics APIs?

A: No. The AMD Instinct MI455X lists DirectX, OpenGL, and Vulkan as N/A. The NVIDIA RTX PRO 6000 Blackwell supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4.

Q: Which card has a higher FP32 compute rating?

A: The AMD Instinct MI455X delivers 157.3 TFLOPS FP32, while the NVIDIA RTX PRO 6000 Blackwell delivers 126.0 TFLOPS FP32.

Q: What is the only recorded 3DMark benchmark score in the database?

A: The NVIDIA RTX PRO 6000 Blackwell has a 3DMark Steel Nomad DX12 score of 16408. The AMD Instinct MI455X has no benchmark entries in the database.

Architecture Differences

The AMD Instinct MI455X is built on the CDNA 5.0 architecture using a 2 nm TSMC process with the MI450 256CU chip. The design uses 320,000 million transistors on a 2990 mm² die, which results in a transistor density of 107.0M per mm². The NVIDIA RTX PRO 6000 Blackwell uses the Blackwell 2.0 architecture with the GB202 chip, fabricated on a 5 nm TSMC process. It contains 92,200 million transistors on a 750 mm² die, giving a higher transistor density of 122.9M per mm².

The AMD card is a compute-focused accelerator with 32768 shading units and 1024 TMUs, but it has 0 ROPs and a pixel rate of 0 MPixel/s. It has no display outputs and no graphics API support. The NVIDIA card, by contrast, is a full workstation GPU with 24064 shading units, 752 TMUs, and 192 ROPs. It includes 188 RT cores and 752 tensor cores, features absent from the AMD card's listed specifications. The NVIDIA card also has 4x DisplayPort 2.1b outputs and full DirectX, OpenGL, and Vulkan support.

Memory architecture differs sharply. The AMD Instinct MI455X uses 432 GB of HBM4 on a 24576-bit bus, achieving 23.3 TB/s of bandwidth. The NVIDIA RTX PRO 6000 Blackwell uses 96 GB of GDDR7 on a 512-bit bus, achieving 1.79 TB/s of bandwidth. The AMD card's memory subsystem is designed for massive data movement, while the NVIDIA card's smaller, faster-clocked GDDR7 memory suits workstation graphics workloads.

The physical and power designs also diverge. The AMD card is an EAM Module with no power connectors and a 2300 W TDP, requiring a suggested PSU of 2700 W. The NVIDIA card is a dual-slot design with a 1x 16-pin power connector, a 600 W TDP, and a suggested PSU of 1000 W. The NVIDIA card measures 304 mm in length, 137 mm in height, and 40 mm in width. The AMD card's dimensions are not recorded.

Head-to-Head Benchmarks

The database contains no direct head-to-head benchmark results between the AMD Instinct MI455X and the NVIDIA RTX PRO 6000 Blackwell. The AMD card has no benchmark scores listed at all, and its average benchmark score is 0. The NVIDIA card has one recorded result: 16408 in 3DMark Steel Nomad DX12.

The NVIDIA card's nearest rivals in the database provide context for that score. The AMD Radeon PRO W7500 scores 16415, which is a delta of 0% relative to the RTX PRO 6000 Blackwell. The AMD Radeon RX 5700 XT scores 16361, a delta of 0.3% slower. The AMD Radeon Pro 5600M scores 16351, a delta of 0.4% slower. The NVIDIA GeForce RTX 5090 D V2 scores 16504, which is 0.6% faster than the RTX PRO 6000 Blackwell.

These results show that the RTX PRO 6000 Blackwell sits in a cluster of GPUs with very close 3DMark Steel Nomad DX12 performance. The difference between the slowest and fastest of these rivals is only about 0.9%. The RTX PRO 6000 Blackwell's percentile rank among all GPUs is 59, which places it above the median but not at the top of the database.

Because the AMD Instinct MI455X has no recorded benchmarks, no direct comparison of measured performance is possible. The only meaningful comparison comes from the theoretical specifications listed for each card. The AMD card's FP32 throughput of 157.3 TFLOPS is 24.8% higher than the NVIDIA card's 126.0 TFLOPS. The AMD card's texture rate of 2,457.6 GTexel/s is 24.9% higher than the NVIDIA card's 1,968.0 GTexel/s. The NVIDIA card, however, has a pixel rate of 502.5 GPixel/s, while the AMD card has none.

Specification Differences

The two cards differ across nearly every major specification category.

Process and die: AMD uses 2 nm TSMC with 320,000 million transistors on a 2990 mm² die. NVIDIA uses 5 nm TSMC with 92,200 million transistors on a 750 mm² die. Transistor density favors NVIDIA at 122.9M per mm² versus AMD's 107.0M per mm².

Clocks: AMD base clock is 1000 MHz with a boost of 2400 MHz. NVIDIA base clock is 1590 MHz with a boost of 2617 MHz. Memory clock differs as well: AMD runs at 1900 MHz (7.6 Gbps effective), NVIDIA at 1750 MHz (28 Gbps effective).

Memory: AMD has 432 GB of HBM4 on a 24576-bit bus with 23.3 TB/s bandwidth. NVIDIA has 96 GB of GDDR7 on a 512-bit bus with 1.79 TB/s bandwidth.

Compute units: AMD has 32768 shading units, 1024 TMUs, and 0 ROPs. NVIDIA has 24064 shading units, 752 TMUs, and 192 ROPs. NVIDIA has 188 RT cores and 752 tensor cores; AMD lists none.

Rates: AMD pixel rate is 0 MPixel/s, texture rate is 2,457.6 GTexel/s, FP32 is 157.3 TFLOPS, and FP16 is 157.3 TFLOPS (1:1). NVIDIA pixel rate is 502.5 GPixel/s, texture rate is 1,968.0 GTexel/s, FP32 is 126.0 TFLOPS, and FP16 is 126.0 TFLOPS (1:1).

Power and cooling: AMD TDP is 2300 W with no power connectors and a suggested PSU of 2700 W. NVIDIA TDP is 600 W with 1x 16-pin power connector and a suggested PSU of 1000 W.

Form factor: AMD is an EAM Module. NVIDIA is dual-slot with dimensions of 304 mm length, 137 mm height, and 40 mm width.

Interface and outputs: AMD uses PCIe 6.0 x16 and has no display outputs. NVIDIA uses PCIe 5.0 x16 and has 4x DisplayPort 2.1b outputs.

APIs: AMD lists DirectX, OpenGL, and Vulkan as N/A. NVIDIA supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4.

Release dates: AMD released on 2026-07-22. NVIDIA released on 2025-03-17. The NVIDIA card has a launch MSRP of 8,565 USD; AMD has no recorded MSRP. Production status for AMD is not recorded; NVIDIA is listed as Active.

Where Each One Wins

The AMD Instinct MI455X wins in raw compute throughput. Its FP32 and FP16 figures of 157.3 TFLOPS are the highest recorded in this comparison. Its texture rate of 2,457.6 GTexel/s also leads. The memory subsystem is the AMD card's strongest feature: 432 GB of HBM4 with 23.3 TB/s of bandwidth, a capacity and bandwidth combination that dominates the NVIDIA card's 96 GB and 1.79 TB/s. For workloads that move very large datasets, such as AI training or scientific simulation, the AMD card's memory capacity and bandwidth are the decisive factors. Its PCIe 6.0 x16 interface is also a generation ahead of NVIDIA's PCIe 5.0 x16.

The NVIDIA RTX PRO 6000 Blackwell wins in graphics and workstation features. It has 192 ROPs and a pixel rate of 502.5 GPixel/s, while the AMD card has none. It includes 188 RT cores and 752 tensor cores. It supports DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4, and provides 4x DisplayPort 2.1b outputs. The AMD card has no display outputs and no API support, so it cannot drive a monitor or run standard graphics applications. The NVIDIA card also has a much lower TDP of 600 W versus 2300 W, a dual-slot form factor that fits standard workstation chassis, and a 1x 16-pin power connector. Its higher boost clock of 2617 MHz and base clock of 1590 MHz reflect a design tuned for sustained graphics workloads.

The measured benchmark data also favors NVIDIA, since it has a recorded 3DMark Steel Nomad DX12 score of 16408 and a percentile rank of 59. The AMD card has no recorded benchmark scores, so its real-world performance cannot be verified from the database. The NVIDIA card's nearest rivals are all within 0.6% of its score, indicating that it performs in line with a tight group of established GPUs.

The Verdict

The data separates these two cards by intended use, not by a single performance number. The AMD Instinct MI455X is a compute accelerator with no graphics capability. It offers 157.3 TFLOPS FP32, 432 GB of HBM4 memory, 23.3 TB/s of bandwidth, and a 2300 W TDP. It is designed for environments where massive memory capacity and raw compute matter more than display output or API compatibility. The lack of ROPs, display outputs, and graphics API support confirms that it is not a workstation graphics card.

The NVIDIA RTX PRO 6000 Blackwell is a full workstation GPU. It has 192 ROPs, 188 RT cores, 752 tensor cores, 4x DisplayPort 2.1b outputs, and full DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4 support. Its 3DMark Steel Nomad DX12 score of 16408 places it within 0.6% of its nearest rivals. Its 600 W TDP, dual-slot form factor, and 1x 16-pin power connector make it installable in conventional workstation systems. Its launch MSRP is 8,565 USD.

The choice between them depends entirely on the workload. For compute-heavy tasks that need enormous memory capacity and bandwidth, the AMD Instinct MI455X is the card the specifications support. For graphics rendering, real-time visualization, API-compatible workstation applications, or any use requiring a display output, the NVIDIA RTX PRO 6000 Blackwell is the only viable option in this comparison. The database contains no benchmark results for the AMD card, so its theoretical advantages cannot be confirmed with measured data. The NVIDIA card has a recorded benchmark score and a percentile rank of 59, giving it the only verified performance data in this pairing.