AMD Instinct MI455X vs AMD Radeon RX 6550M Comparison

Head-to-Head Benchmarks

The recorded data for the AMD Instinct MI455X contains no benchmark entries, while the AMD Radeon RX 6550M has two recorded results. This makes direct head-to-head comparison impossible from the database. The RX 6550M posts a Geekbench OpenCL score of 42,536 and a Geekbench Vulkan score of 50,867, giving it an average benchmark score of 46,702. The MI455X has an average benchmark score of 0, placing it at the 50th percentile among all GPUs, while the RX 6550M sits at the 85th percentile.

Because the MI455X has no benchmark scores, the biggest wins for the RX 6550M are straightforward: it delivers measurable compute performance in both OpenCL and Vulkan workloads, whereas the MI455X has no recorded test results. The RX 6550M also outscores its nearest rivals in the database. It leads the Intel Arc A530M by 0.2% (46,702 vs 46,614), matches the AMD Radeon RX 5600M within 0.2% (46,702 vs 46,601), and beats the NVIDIA RTX A2000 by 1.4% (46,702 vs 46,043) and the NVIDIA RTX 5880 Ada Generation by 1.6% (46,702 vs 45,972).

The MI455X, lacking any benchmark data, cannot demonstrate wins in any tested workload. Its 50th percentile ranking with a score of 0 reflects an absence of recorded performance, not a measured performance level. The RX 6550M, by contrast, has a fully populated benchmark profile. The data shows the RX 6550M as the only one of the pair with verifiable compute results.

Where Each One Wins

Based strictly on benchmark data, the AMD Radeon RX 6550M wins in every measurable category. Its Vulkan score of 50,867 exceeds its OpenCL score of 42,536, indicating stronger performance in Vulkan-based workloads. The average benchmark score of 46,702 places it above all four nearest rivals listed in the database. The RX 6550M also has a production status of "Active," meaning it is currently available in the market.

The AMD Instinct MI455X has no recorded wins because it has no benchmark entries. Its 50th percentile ranking with an average score of 0 means the database contains no evidence of its compute capabilities. The MI455X does have a higher raw specification profile, including a 2 nm process node, 320,000 million transistors, and 157.3 TFLOPS FP32 performance, but these are architectural specifications, not benchmark results. Without test data, the database cannot confirm any workload advantage for the MI455X.

For use-case analysis, the RX 6550M shows clear applicability to portable devices, as its display outputs are "Portable Device Dependent" and its slot width is "IGP." Its 4 GB GDDR6 memory with 144.0 GB/s bandwidth suits lighter graphics workloads. The MI455X, with 432 GB HBM4 memory and 23.3 TB/s bandwidth, appears oriented toward memory-intensive compute applications, but the lack of benchmark scores means the database provides no performance confirmation. The wins in this comparison belong exclusively to the RX 6550M.

Architecture Differences

The AMD Instinct MI455X uses the CDNA 5.0 architecture with a chip labeled "MI450 256CU," manufactured on a 2 nm process at TSMC. It packs 320,000 million transistors onto a 2990 mm² die, yielding a transistor density of 107.0M per mm². The RX 6550M uses the RDNA 2.0 architecture with a Navi 24 chip, built on a 6 nm process also at TSMC. It contains 5,400 million transistors on a 107 mm² die, with a density of 50.5M per mm². The MI455X has roughly 59 times more transistors and a die about 28 times larger.

The MI455X includes 32,768 shading units, 1,024 texture mapping units, and 0 ROPs. Its pixel rate is recorded as 0 MPixel/s, and its texture rate is 2,457.6 GTexel/s. It delivers 157.3 TFLOPS for both FP32 and FP16 (1:1 ratio). The RX 6550M has 1,024 shading units, 64 TMUs, and 32 ROPs, with a pixel rate of 90.88 GPixel/s and a texture rate of 181.8 GTexel/s. Its FP32 performance is 5.816 TFLOPS, and FP16 performance is 11.63 TFLOPS (2:1 ratio). The MI455X offers about 27 times the FP32 throughput of the RX 6550M on paper.

Memory configurations differ drastically. The MI455X uses 432 GB of HBM4 across a 24576-bit bus, delivering 23.3 TB/s bandwidth. The RX 6550M uses 4 GB of GDDR6 on a 64-bit bus, with 144.0 GB/s bandwidth. The MI455X has no display outputs, while the RX 6550M has display outputs described as "Portable Device Dependent." The MI455X supports no DirectX, OpenGL, or Vulkan APIs, whereas the RX 6550M supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. The MI455X has 16 ray tracing cores absent in the MI455X specification, as it shows no RT cores.

Clock speeds also differ. The MI455X has a base clock of 1000 MHz and a boost clock of 2400 MHz, with memory at 1900 MHz (7.6 Gbps effective). The RX 6550M has a base clock of 2000 MHz, a boost clock of 2840 MHz, a game clock of 2560 MHz, and memory at 2250 MHz (18 Gbps effective). The RX 6550M runs at higher clock frequencies, while the MI455X relies on a vastly larger compute array.

Power and interface specs diverge as well. The MI455X has a TDP of 2300 W and a suggested PSU of 2700 W, with a slot width of "EAM Module" and a PCIe 6.0 x16 bus interface. The RX 6550M has a TDP of 80 W, no suggested PSU listed, an "IGP" slot width, and a PCIe 4.0 x4 bus interface. Neither uses external power connectors. The MI455X was released on 2026-07-22, while the RX 6550M was released on 2023-01-03. The MI455X belongs to the Instinct (MIx) generation with a predecessor of Radeon Instinct, while the RX 6550M belongs to the Navi Mobile (RX 6000M) generation with a predecessor of Polaris Mobile.

The Verdict

The database presents a clear but one-sided picture. The AMD Radeon RX 6550M is the only one of the two with recorded benchmark performance. Its average score of 46,702, 85th percentile ranking, and wins over four nearest rivals (Intel Arc A530M, AMD Radeon RX 5600M, NVIDIA RTX A2000, NVIDIA RTX 5880 Ada Generation) confirm it as a functional, measurable graphics processor for portable systems. Its Active production status and API support (DirectX 12 Ultimate, OpenGL 4.6, Vulkan 1.4) make it usable in standard software environments.

The AMD Instinct MI455X has no benchmark scores, no API support, and no display outputs. Its 50th percentile ranking with a score of 0 means the database contains zero evidence of its performance in any workload. While its specifications indicate an enormous compute device (157.3 TFLOPS FP32, 432 GB HBM4, 23.3 TB/s bandwidth), none of that is validated by test results. The data cannot recommend the MI455X for any use case because there is no recorded performance to evaluate.

For anyone selecting between these two based on the database, the RX 6550M is the only option with demonstrated capability. The MI455X should only be considered if its unverified specifications align with a need for extreme memory capacity and raw compute density, but the absence of benchmark data means the database cannot support such a choice. The verdict is straightforward: the RX 6550M wins on evidence, while the MI455X wins only on paper specifications.

FAQ

Q: Which GPU has a higher average benchmark score?

A: The AMD Radeon RX 6550M has an average benchmark score of 46,702, while the AMD Instinct MI455X has an average benchmark score of 0.

Q: What are the recorded benchmark scores for the RX 6550M?

A: The RX 6550M scores 42,536 in Geekbench OpenCL and 50,867 in Geekbench Vulkan.

Q: Does the MI455X support DirectX or Vulkan?

A: No, the MI455X lists DirectX, OpenGL, and Vulkan as "N/A." The RX 6550M supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4.

Q: How much memory does each GPU have?

A: The MI455X has 432 GB of HBM4 memory with a 24576-bit bus and 23.3 TB/s bandwidth. The RX 6550M has 4 GB of GDDR6 memory with a 64-bit bus and 144.0 GB/s bandwidth.

Q: What is the transistor count difference?

A: The MI455X contains 320,000 million transistors on a 2990 mm² die, while the RX 6550M contains 5,400 million transistors on a 107 mm² die.

Q: Which GPU has a higher boost clock?

A: The RX 6550M has a boost clock of 2840 MHz, compared to the MI455X boost clock of 2400 MHz.

Specification Differences

| Specification | AMD Instinct MI455X | AMD Radeon RX 6550M |

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

| Architecture | CDNA 5.0 | RDNA 2.0 |

| Chip | MI450 256CU | Navi 24 |

| Process Node | 2 nm | 6 nm |

| Transistors | 320,000 million | 5,400 million |

| Die Size | 2990 mm² | 107 mm² |

| Transistor Density | 107.0M / mm² | 50.5M / mm² |

| Base Clock | 1000 MHz | 2000 MHz |

| Boost Clock | 2400 MHz | 2840 MHz |

| Game Clock | None | 2560 MHz |

| Memory Clock | 1900 MHz (7.6 Gbps effective) | 2250 MHz (18 Gbps effective) |

| Memory Size | 432 GB | 4 GB |

| Memory Type | HBM4 | GDDR6 |

| Memory Bus Width | 24576 bit | 64 bit |

| Memory Bandwidth | 23.3 TB/s | 144.0 GB/s |

| Shading Units | 32768 | 1024 |

| TMUs | 1024 | 64 |

| ROPs | 0 | 32 |

| RT Cores | None | 16 |

| Pixel Rate | 0 MPixel/s | 90.88 GPixel/s |

| Texture Rate | 2,457.6 GTexel/s | 181.8 GTexel/s |

| FP32 Performance | 157.3 TFLOPS | 5.816 TFLOPS |

| FP16 Performance | 157.3 TFLOPS (1:1) | 11.63 TFLOPS (2:1) |

| TDP | 2300 W | 80 W |

| Slot Width | EAM Module | IGP |

| Suggested PSU | 2700 W | None |

| Bus Interface | PCIe 6.0 x16 | PCIe 4.0 x4 |

| Display Outputs | No outputs | Portable Device Dependent |

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

| OpenGL Support | N/A | 4.6 |

| Vulkan Support | N/A | 1.4 |

| Production Status | None listed | Active |

| Release Date | 2026-07-22 | 2023-01-03 |

| Predecessor | Radeon Instinct | Polaris Mobile |

| Average Benchmark Score | 0 | 46,702 |

| Percentile vs All GPUs | 50 | 85 |