AMD Instinct MI455X vs AMD Ryzen Z1 GPU Comparison

Head-to-Head Benchmarks

The database contains no recorded benchmark scores for either the AMD Instinct MI455X or the AMD Ryzen Z1 GPU. Both entries show an average benchmark score of 0 and a percentile rank of 50 against all GPUs. With zero wins recorded for each side and no head-to-head benchmark entries, direct performance comparisons must be derived from the architectural specifications and compute capabilities listed in the database.

The Instinct MI455X presents a raw compute profile that dwarfs the Ryzen Z1 GPU in nearly every measured throughput category. Its FP32 output reaches 157.3 TFLOPS, which is 61.4 times higher than the Ryzen Z1 GPU's 2.560 TFLOPS. The FP16 figures further separate the two: the MI455X delivers 157.3 TFLOPS with a 1:1 ratio, while the Ryzen Z1 GPU produces 5.120 TFLOPS at a 2:1 ratio. The texture rate difference is equally stark, with the MI455X achieving 2,457.6 GTexel/s versus 40.00 GTexel/s for the Ryzen Z1 GPU, a 61.4-fold gap.

Memory bandwidth tells a similar story. The MI455X accesses 432 GB of HBM4 across a 24576-bit bus, yielding 23.3 TB/s of bandwidth. The Ryzen Z1 GPU uses 16 GB of LPDDR5 on a 64-bit bus, producing 51.20 GB/s. That puts the MI455X at 455 times the memory bandwidth of the Ryzen Z1 GPU. The pixel rate also diverges completely: the MI455X lists 0 MPixel/s, while the Ryzen Z1 GPU manages 20.00 GPixel/s.

The Ryzen Z1 GPU does hold advantages in certain architectural features. Its boost clock of 2500 MHz exceeds the MI455X's 2400 MHz boost. The Ryzen Z1 GPU also carries 4 ray tracing cores, while the MI455X has none listed. The Ryzen Z1 GPU supports DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4, while the MI455X lists N/A for all three APIs, reflecting its compute-oriented design with no display outputs.

FAQ

Q: Which GPU has higher FP32 compute performance?

A: The AMD Instinct MI455X delivers 157.3 TFLOPS FP32, which is 61.4 times the 2.560 TFLOPS FP32 of the AMD Ryzen Z1 GPU.

Q: What memory configuration does each GPU use?

A: The MI455X uses 432 GB of HBM4 on a 24576-bit bus with 23.3 TB/s bandwidth. The Ryzen Z1 GPU uses 16 GB of LPDDR5 on a 64-bit bus with 51.20 GB/s bandwidth.

Q: Does the Ryzen Z1 GPU support ray tracing?

A: Yes, the Ryzen Z1 GPU has 4 ray tracing cores. The MI455X has no ray tracing cores listed in the database.

Q: Which GPU has a higher boost clock?

A: The Ryzen Z1 GPU boosts to 2500 MHz, while the MI455X boosts to 2400 MHz. The Ryzen Z1 GPU also has a higher base clock at 1500 MHz versus 1000 MHz.

Q: What process nodes are used for each chip?

A: The MI455X uses a 2 nm process from TSMC with a die size of 2990 mm² and 320,000 million transistors. The Ryzen Z1 GPU uses a 4 nm process from TSMC with a die size of 178 mm² and 25,390 million transistors.

Q: What is the power consumption of each GPU?

A: The MI455X has a TDP of 2300 W with a suggested PSU of 2700 W. The Ryzen Z1 GPU has a TDP of 30 W and no suggested PSU listed.

Architecture Differences

The two GPUs come from different architectural lineages within AMD's product stack. The MI455X is built on CDNA 5.0 architecture, designed for compute acceleration with a chip labeled "MI450 256CU." The Ryzen Z1 GPU uses RDNA 3.0 architecture on a chip called "Phoenix," targeting console and mobile graphics workloads.

The MI455X uses a 2 nm process node from TSMC with 320,000 million transistors packed into a 2990 mm² die. That yields a transistor density of 107.0M per mm². The Ryzen Z1 GPU uses a 4 nm process from the same foundry, with 25,390 million transistors on a 178 mm² die, achieving a higher density of 142.6M per mm². Despite being on an older node, the Ryzen Z1 GPU packs transistors more tightly per square millimeter.

Shading unit counts diverge massively. The MI455X has 32,768 shading units, 1,024 texture mapping units, and 0 ROPs. The Ryzen Z1 GPU has 256 shading units, 16 TMUs, and 8 ROPs. The MI455X's compute-heavy design omits ROPs entirely, which aligns with its 0 MPixel/s pixel rate. The Ryzen Z1 GPU includes ROPs and produces 20.00 GPixel/s.

Memory technology differs completely. The MI455X uses HBM4 with a 24576-bit bus, while the Ryzen Z1 GPU uses LPDDR5 on a 64-bit bus. The MI455X's memory clock is 1900 MHz with 7.6 Gbps effective, while the Ryzen Z1 GPU runs at 800 MHz with 6.4 Gbps effective.

The MI455X supports no display outputs and has no API support listed for DirectX, OpenGL, or Vulkan. The Ryzen Z1 GPU also has no display outputs but supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4.

Power delivery differs fundamentally. The MI455X draws 2300 W TDP with a suggested 2700 W PSU, using an EAM Module slot width and no power connectors. The Ryzen Z1 GPU draws 30 W TDP with no suggested PSU and no power connectors. The MI455X connects via PCIe 6.0 x16, while the Ryzen Z1 GPU's bus interface is not listed.

The MI455X is part of the Instinct (MIx) generation and was released on 2026-07-22. Its predecessor is Radeon Instinct. The Ryzen Z1 GPU belongs to the Console GPU (AMD) generation and was released on 2023-09-17, with a production status of Active. The MI455X has no production status listed.

The Verdict

The data supports a clear split by workload type. The MI455X is a compute accelerator with extreme throughput in FP32 and FP16, massive memory capacity and bandwidth, and no graphics output or API support. It targets workloads where raw arithmetic and memory throughput dominate, such as large-scale training or inference tasks.

The Ryzen Z1 GPU is a low-power graphics processor with ray tracing support and full API compatibility. Its 30 W TDP and 16 GB memory make it suitable for embedded or console applications where power constraints matter. The Ryzen Z1 GPU's higher boost clock (2500 MHz vs 2400 MHz) and ray tracing cores give it capabilities the MI455X lacks.

The MI455X leads decisively in compute metrics: 61.4 times the FP32 throughput, 61.4 times the texture rate, and 455 times the memory bandwidth. The Ryzen Z1 GPU leads in pixel rate (20.00 GPixel/s vs 0 MPixel/s), ray tracing support, API compatibility, and power efficiency.

Neither GPU shows a benchmark advantage in the database because no recorded scores exist. The architectural data alone determines the verdict: the MI455X for pure compute density, the Ryzen Z1 GPU for graphics-oriented tasks within a low-power envelope.

Specification Differences

| Specification | AMD Instinct MI455X | AMD Ryzen Z1 GPU |

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

| Architecture | CDNA 5.0 | RDNA 3.0 |

| Chip | MI450 256CU | Phoenix |

| Process Node | 2 nm | 4 nm |

| Transistors | 320,000 million | 25,390 million |

| Die Size | 2990 mm² | 178 mm² |

| Transistor Density | 107.0M / mm² | 142.6M / mm² |

| Base Clock | 1000 MHz | 1500 MHz |

| Boost Clock | 2400 MHz | 2500 MHz |

| Memory Clock | 1900 MHz, 7.6 Gbps effective | 800 MHz, 6.4 Gbps effective |

| Memory Size | 432 GB | 16 GB |

| Memory Type | HBM4 | LPDDR5 |

| Memory Bus Width | 24576 bit | 64 bit |

| Memory Bandwidth | 23.3 TB/s | 51.20 GB/s |

| Shading Units | 32768 | 256 |

| TMUs | 1024 | 16 |

| ROPs | 0 | 8 |

| Ray Tracing Cores | None | 4 |

| Pixel Rate | 0 MPixel/s | 20.00 GPixel/s |

| Texture Rate | 2,457.6 GTexel/s | 40.00 GTexel/s |

| FP32 | 157.3 TFLOPS | 2.560 TFLOPS |

| FP16 | 157.3 TFLOPS (1:1) | 5.120 TFLOPS (2:1) |

| TDP | 2300 W | 30 W |

| Slot Width | EAM Module | Not listed |

| Bus Interface | PCIe 6.0 x16 | Not listed |

| API Support | DirectX N/A, OpenGL N/A, Vulkan N/A | DirectX 12 Ultimate, OpenGL 4.6, Vulkan 1.4 |

| Release Date | 2026-07-22 | 2023-09-17 |

| Production Status | Not listed | Active |

The MI455X has a launch MSRP of none listed, while the Ryzen Z1 GPU has a launch MSRP of 599 USD.

Where Each One Wins

Compute throughput: The MI455X dominates with 157.3 TFLOPS FP32 and FP16, 2,457.6 GTexel/s texture rate, and 23.3 TB/s memory bandwidth. These figures make it suited for workloads that process large matrices or data arrays continuously.

Memory capacity and bandwidth: The MI455X offers 432 GB of HBM4 memory versus 16 GB of LPDDR5, and 23.3 TB/s versus 51.20 GB/s. Applications requiring large in-memory datasets or high-speed data streaming favor the MI455X.

Graphics rendering: The Ryzen Z1 GPU wins with 20.00 GPixel/s pixel rate, 8 ROPs, and 4 ray tracing cores. The MI455X has 0 ROPs and no ray tracing support, making it incapable of conventional rasterization.

API and software compatibility: The Ryzen Z1 GPU supports DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4, while the MI455X lists N/A for all three. Graphics applications and game engines require the Ryzen Z1 GPU's API stack.

Power efficiency: The Ryzen Z1 GPU consumes 30 W TDP versus 2300 W for the MI455X. For deployments with strict power budgets or thermal limits, the Ryzen Z1 GPU is the only viable option.

Clock speed: The Ryzen Z1 GPU operates at 1500 MHz base and 2500 MHz boost, both higher than the MI455X's 1000 MHz base and 2400 MHz boost. Higher clocks benefit latency-sensitive or lightly parallel workloads.

Transistor density: The Ryzen Z1 GPU achieves 142.6M transistors per mm² versus 107.0M for the MI455X, indicating more efficient use of die area.

The MI455X uses a 2 nm process with 320,000 million transistors, while the Ryzen Z1 GPU uses a 4 nm process with 25,390 million transistors. The MI455X has a 2990 mm² die and no display outputs. The Ryzen Z1 GPU has a 178 mm² die, measures 280 mm by 111 mm by 21 mm, and also has no display outputs.