AMD Instinct MI455X vs AMD Ryzen Z2 Extreme GPU Comparison

The AMD Instinct MI455X and the AMD Ryzen Z2 Extreme GPU occupy opposite ends of the hardware spectrum. The MI455X is a compute-oriented accelerator with a 2300 W TDP, while the Z2 Extreme GPU is a 28 W console-class integrated graphics solution. The recorded data shows no shared benchmark suite, as the MI455X has no benchmark entries in the database, whereas the Z2 Extreme GPU has a single 3DMark Steel Nomad DX12 score of 516. The MI455X holds a 50th percentile ranking among all GPUs, while the Z2 Extreme GPU sits at the 1st percentile. This difference in percentile indicates that the MI455X is positioned in the middle of the database’s recorded performance distribution, while the Z2 Extreme GPU resides near the lower boundary.

The Verdict

The data indicates a clear separation of roles. The AMD Instinct MI455X is the choice for workloads that demand massive compute throughput, with 157.3 TFLOPS of FP32 performance and 23.3 TB/s of memory bandwidth. Its 432 GB of HBM4 memory and 24576-bit bus width position it for large-scale data processing. The AMD Ryzen Z2 Extreme GPU, by contrast, delivers 5.530 TFLOPS of FP32 performance and 128.0 GB/s of bandwidth, with 16 GB of LPDDR5X memory. The Z2 Extreme GPU’s single benchmark score of 516 in 3DMark Steel Nomad DX12 places it 3.4% behind the Intel HD Graphics P4000 and 3.7% behind the AMD Radeon HD 6870, while it leads the AMD Radeon HD 6750M by 6.6%. The MI455X, with no recorded benchmarks, cannot be compared directly on the same tests, but its percentile rank of 50 versus the Z2 Extreme GPU’s rank of 1 suggests a substantial performance gap in the database’s overall distribution.

For buyers, the decision rests on the intended use case. The MI455X is a server or datacenter part, evidenced by its EAM Module slot width, lack of display outputs, and PCIe 6.0 x16 interface. The Z2 Extreme GPU is a mobile or embedded part with a single USB Type-C display output. The MI455X has no API support for DirectX, OpenGL, or Vulkan, while the Z2 Extreme GPU supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. The MI455X targets compute acceleration, not graphics rendering. The Z2 Extreme GPU targets graphics output. The data does not support a single winner across all tasks; it supports two distinct products with different purposes.

Where Each One Wins

The MI455X wins decisively on raw compute resources. It has 32768 shading units, 1024 TMUs, and a texture rate of 2,457.6 GTexel/s. The Z2 Extreme GPU has 1024 shading units, 64 TMUs, and a texture rate of 172.8 GTexel/s. The MI455X’s FP32 throughput of 157.3 TFLOPS is roughly 28 times the Z2 Extreme GPU’s 5.530 TFLOPS. The MI455X also leads on memory: 432 GB versus 16 GB, 23.3 TB/s versus 128.0 GB/s, and a 24576-bit bus width versus 128-bit. The MI455X’s pixel rate is 0 MPixel/s, meaning it does not process pixels in the traditional graphics pipeline, while the Z2 Extreme GPU delivers 129.6 GPixel/s with 48 ROPs.

The Z2 Extreme GPU wins on graphics feature support and efficiency. It includes 16 ray tracing cores, which the MI455X does not list. It supports DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4, whereas the MI455X reports N/A for all three APIs. The Z2 Extreme GPU operates at a 28 W TDP, and its boost clock of 2700 MHz exceeds the MI455X’s boost clock of 2400 MHz. The Z2 Extreme GPU’s production status is Active, while the MI455X lists no production status. The Z2 Extreme GPU has a single display output, making it usable in a graphics context, while the MI455X has no outputs. The Z2 Extreme GPU’s 1st percentile rank is low, but it has a recorded benchmark score, unlike the MI455X’s empty benchmark array.

Architecture Differences

The MI455X uses the CDNA 5.0 architecture on a 2 nm TSMC process, while the Z2 Extreme GPU uses RDNA 3.5 on a 4 nm TSMC process. The MI455X’s chip is designated MI450 256CU, and the Z2 Extreme GPU’s chip is Strix Point. The MI455X contains 320,000 million transistors on a 2990 mm² die, yielding a density of 107.0M transistors per mm². The Z2 Extreme GPU contains 34,000 million transistors on a 233 mm² die, yielding a density of 145.9M transistors per mm². The MI455X’s die is substantially larger, but the Z2 Extreme GPU achieves higher transistor density.

Memory architecture differs sharply. The MI455X uses 432 GB of HBM4 with a 24576-bit bus and 23.3 TB/s bandwidth. The Z2 Extreme GPU uses 16 GB of LPDDR5X with a 128-bit bus and 128.0 GB/s bandwidth. The MI455X’s memory clock is 1900 MHz with 7.6 Gbps effective, while the Z2 Extreme GPU’s memory clock is 1000 MHz with 8 Gbps effective. The MI455X’s base clock is 1000 MHz and boost is 2400 MHz. The Z2 Extreme GPU’s base clock is 800 MHz and boost is 2700 MHz. The Z2 Extreme GPU has a higher boost clock despite a lower base clock.

The MI455X has no ROPs, no ray tracing cores, and no API support. Its pixel rate is 0 MPixel/s. The Z2 Extreme GPU has 48 ROPs, 16 ray tracing cores, and full API support for modern graphics standards. The MI455X’s power connectors are listed as None, and it requires a suggested PSU of 2700 W. The Z2 Extreme GPU also has no power connectors, but it has no suggested PSU listed. The MI455X’s slot width is EAM Module, which indicates a non-standard form factor, while the Z2 Extreme GPU’s slot width is not listed. The MI455X uses PCIe 6.0 x16, while the Z2 Extreme GPU has no bus interface listed.

FAQ

Q: Which GPU has more shading units?

A: The AMD Instinct MI455X has 32768 shading units. The AMD Ryzen Z2 Extreme GPU has 1024 shading units.

Q: What is the memory bandwidth difference?

A: The MI455X provides 23.3 TB/s of bandwidth from 432 GB of HBM4 memory on a 24576-bit bus. The Z2 Extreme GPU provides 128.0 GB/s from 16 GB of LPDDR5X memory on a 128-bit bus.

Q: Does the MI455X support DirectX?

A: No. The MI455X lists DirectX as N/A. The Z2 Extreme GPU supports DirectX 12 Ultimate (12_2).

Q: How does the Z2 Extreme GPU compare to its nearest rivals?

A: The Z2 Extreme GPU’s 3DMark Steel Nomad DX12 score of 516 is 3.4% below the Intel HD Graphics P4000’s 534 and 3.7% below the AMD Radeon HD 6870’s 536. It is 6.6% above the AMD Radeon HD 6750M’s 484 and 9.3% below the AMD Radeon HD 6770M’s 569.

Q: What is the TDP of each GPU?

A: The MI455X has a TDP of 2300 W. The Z2 Extreme GPU has a TDP of 28 W.

Q: Which GPU has ray tracing cores?

A: The Z2 Extreme GPU has 16 ray tracing cores. The MI455X does not list any ray tracing cores.

Head-to-Head Benchmarks

The database contains no shared head-to-head benchmark entries for these two GPUs. The MI455X has an empty benchmark array and an average benchmark score of 0. The Z2 Extreme GPU has one recorded benchmark: 3DMark Steel Nomad DX12 with a score of 516 and an average benchmark score of 516. Any comparison between the two must rely on the recorded specifications and the Z2 Extreme GPU’s rival comparisons.

The largest statistical gap in the Z2 Extreme GPU’s data is against the AMD Radeon HD 6770M, which scores 569, a 9.3% lead over the Z2 Extreme GPU’s 516. The smallest gap is against the Intel HD Graphics P4000 at 534, which leads by 3.4%. The AMD Radeon HD 6870 scores 536, a 3.7% lead. The only rival the Z2 Extreme GPU beats is the AMD Radeon HD 6750M at 484, a 6.6% margin. These figures show the Z2 Extreme GPU clustering with older discrete and integrated graphics parts in the low end of the database’s performance distribution.

The MI455X’s 50th percentile ranking, despite no benchmark scores, indicates that the database assigns it a median position based on its recorded specifications. The Z2 Extreme GPU’s 1st percentile ranking places it among the lowest-performing entries. The MI455X’s raw compute figures dwarf the Z2 Extreme GPU’s: 157.3 TFLOPS versus 5.530 TFLOPS in FP32, 2,457.6 GTexel/s versus 172.8 GTexel/s in texture rate, and 23.3 TB/s versus 128.0 GB/s in memory bandwidth. The Z2 Extreme GPU counters with 129.6 GPixel/s pixel rate versus 0 MPixel/s, and a boost clock of 2700 MHz versus 2400 MHz.

The MI455X’s 2990 mm² die and 320,000 million transistors represent the physical scale of a compute accelerator, while the Z2 Extreme GPU’s 233 mm² die and 34,000 million transistors represent an integrated part. The Z2 Extreme GPU’s higher transistor density of 145.9M per mm², compared to the MI455X’s 107.0M per mm², reflects the different design goals. The MI455X allocates its die to compute units and HBM4 memory controllers, while the Z2 Extreme GPU allocates its die to graphics features and a smaller memory interface.

The MI455X’s release date of 2026-07-22 and the Z2 Extreme GPU’s release date of 2025-07-08 place them in successive years, but the data shows they are not competitors. The MI455X has no predecessor beyond the Radeon Instinct line, while the Z2 Extreme GPU has no predecessor listed. The MI455X’s generation is Instinct (MIx), and the Z2 Extreme GPU’s generation is Console GPU (AMD). The MI455X’s FP16 throughput matches its FP32 at 157.3 TFLOPS (1:1), and the Z2 Extreme GPU’s FP16 also matches its FP32 at 5.530 TFLOPS (1:1). Both parts use TSMC as the foundry, but on different process nodes. The MI455X’s 2 nm process and the Z2 Extreme GPU’s 4 nm process represent the only direct manufacturing link between the two.