AMD Instinct MI455X vs AMD Radeon RX 7600M XT Comparison

Architecture Differences

The AMD Instinct MI455X and AMD Radeon RX 7600M XT represent two entirely different design philosophies from AMD, separated by architecture, process technology, and intended workload. The MI455X uses the CDNA 5.0 architecture, built specifically for compute-intensive data center tasks, while the RX 7600M XT uses the RDNA 3.0 architecture, designed for graphics rendering and gaming on mobile platforms.

The MI455X is fabricated on a 2 nm process at TSMC, housing 320,000 million transistors across a massive 2990 mm² die. This yields a transistor density of 107.0M per mm². The RX 7600M XT, by contrast, uses a 6 nm process also from TSMC, with 13,300 million transistors on a 204 mm² die, giving a density of 65.2M per mm². The difference in scale is staggering: the MI455X packs roughly 24 times more transistors and 14.6 times more die area than the RX 7600M XT.

The MI455X uses an MI450 256CU chip configuration with 32,768 shading units, 1,024 texture mapping units, and zero ROPs. It has no display outputs, no DirectX, OpenGL, or Vulkan API support, and is designed solely for compute workloads. The RX 7600M XT uses the Navi 33 chip with 2,048 shading units, 128 TMUs, 64 ROPs, and 32 ray tracing cores. It supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4, and its display outputs are portable device dependent.

Memory architecture differs fundamentally. The MI455X features 432 GB of HBM4 memory on a 24,576-bit bus, delivering 23.3 TB/s of bandwidth. The RX 7600M XT has 8 GB of GDDR6 memory on a 128-bit bus with 288.0 GB/s bandwidth. The MI455X's memory bandwidth is approximately 80.9 times higher than the mobile GPU's, reflecting the data center part's need to feed 32,768 shading units.

Clock speeds show a different balance. The MI455X runs at a 1000 MHz base and 2400 MHz boost with memory clocked at 1900 MHz (7.6 Gbps effective). The RX 7600M XT runs at 1280 MHz base, 2469 MHz boost, and a 2023 MHz game clock, with memory at 2250 MHz (18 Gbps effective). Despite the MI455X's lower base clock, its raw compute throughput dwarfs the mobile part.

FAQ

Q: What is the primary architectural difference between these two GPUs?

A: The MI455X uses CDNA 5.0, a compute-optimized architecture with no graphics output or API support, while the RX 7600M XT uses RDNA 3.0, a graphics-oriented architecture with full DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4 support.

Q: How do their memory configurations compare?

A: The MI455X has 432 GB of HBM4 memory on a 24,576-bit bus with 23.3 TB/s bandwidth. The RX 7600M XT has 8 GB of GDDR6 on a 128-bit bus with 288.0 GB/s bandwidth.

Q: Which GPU has higher raw FP32 compute performance?

A: The MI455X delivers 157.3 TFLOPS of FP32 compute, compared to 20.23 TFLOPS for the RX 7600M XT. The MI455X is approximately 7.8 times higher in this metric.

Q: What are the power consumption figures for each?

A: The MI455X has a TDP of 2300 W with a suggested PSU of 2700 W, while the RX 7600M XT has a TDP of 120 W. Both use no external power connectors.

Q: When were these products released?

A: The MI455X released on 2026-07-22, while the RX 7600M XT released on 2023-01-03.

Q: What is the form factor and bus interface for each?

A: The MI455X uses an EAM Module slot width with PCIe 6.0 x16, while the RX 7600M XT is an IGP with PCIe 4.0 x16.

Head-to-Head Benchmarks

The database contains benchmark data only for the RX 7600M XT; the MI455X has no recorded benchmark scores. The RX 7600M XT's average benchmark score is 12,710, placing it in the 52nd percentile of all GPUs. Its nearest rivals include the NVIDIA GeForce GTX 670 with an average score of 12,773 and a delta of -0.5%, the NVIDIA Tesla K20Xm at 12,625 with a delta of +0.7%, the NVIDIA GeForce GTX 590 at 12,830 with a delta of -0.9%, and the AMD Radeon Pro 455 at 12,831 with a delta of -0.9%.

In the 3DMark Steel Nomad DX12 test, the RX 7600M XT scores 2,048. This result indicates solid DirectX 12 performance for a mobile GPU, though the exact comparison to the MI455X cannot be made due to missing data.

Geekbench results show the RX 7600M XT scoring 74,869 in OpenCL and 27,793 in Vulkan. The OpenCL score is more than 2.7 times higher than the Vulkan score, which reflects the compute-oriented nature of the OpenCL workload versus the graphics-focused Vulkan test.

PassMark tests reveal a varied performance profile. The RX 7600M XT scores 76 in DirectX 10, 137 in DirectX 11, 58 in DirectX 12, and 175 in DirectX 9. The G2D test shows 894, while the G3D test shows 13,907. The GPU compute score is 7,140. These results indicate that DirectX 9 and DirectX 11 workloads score higher than DirectX 12, which is unusual and suggests driver optimization or architectural preferences for older APIs.

The head-to-head benchmark data between the two GPUs is empty, with zero wins recorded for either side. This means no direct comparative measurements exist in the database, and the analysis must rely on architectural specifications and the RX 7600M XT's standalone benchmarks.

The MI455X's 50th percentile ranking among all GPUs, despite having no recorded benchmarks, is a placeholder position in the database. Its average benchmark score of 0 reflects the absence of test data rather than actual performance.

Specification Differences

The two GPUs differ across nearly every specification category. The MI455X uses CDNA 5.0 architecture with an MI450 256CU chip, while the RX 7600M XT uses RDNA 3.0 with a Navi 33 chip and the codename "Hotpink Bonefish." The MI455X belongs to the Instinct (MIx) generation, while the RX 7600M XT belongs to the Navi Mobile (RX 7000M) generation.

Process technology differs: 2 nm for the MI455X versus 6 nm for the RX 7600M XT, both from TSMC. Transistor counts are 320,000 million versus 13,300 million, and die sizes are 2990 mm² versus 204 mm². Transistor density is 107.0M per mm² versus 65.2M per mm².

Clock specifications show the MI455X at 1000 MHz base and 2400 MHz boost, with memory at 1900 MHz (7.6 Gbps effective). The RX 7600M XT runs at 1280 MHz base, 2469 MHz boost, and 2023 MHz game clock, with memory at 2250 MHz (18 Gbps effective).

Memory capacity is 432 GB of HBM4 versus 8 GB of GDDR6. Bus widths are 24,576 bits versus 128 bits. Bandwidth is 23.3 TB/s versus 288.0 GB/s.

Compute resources: the MI455X has 32,768 shading units, 1,024 TMUs, and 0 ROPs, with no ray tracing cores. The RX 7600M XT has 2,048 shading units, 128 TMUs, 64 ROPs, and 32 ray tracing cores.

Pixel and texture rates: the MI455X has 0 MPixel/s and 2,457.6 GTexel/s, while the RX 7600M XT has 158.0 GPixel/s and 316.0 GTexel/s. FP32 performance is 157.3 TFLOPS versus 20.23 TFLOPS. FP16 performance is 157.3 TFLOPS (1:1) for the MI455X versus 40.45 TFLOPS (2:1) for the RX 7600M XT.

Power and form factor: the MI455X has a TDP of 2300 W with a suggested PSU of 2700 W, and uses an EAM Module slot. The RX 7600M XT has a TDP of 120 W with no suggested PSU, and uses an IGP slot. Both use PCIe x16, but the MI455X uses PCIe 6.0 while the RX 7600M XT uses PCIe 4.0.

Display outputs: the MI455X has none, while the RX 7600M XT has portable device dependent outputs. API support: the MI455X has N/A for DirectX, OpenGL, and Vulkan, while the RX 7600M XT supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4.

Production status: the MI455X has no recorded status, while the RX 7600M XT is listed as Active. Release dates are 2026-07-22 and 2023-01-03 respectively. Predecessors are Radeon Instinct for the MI455X and Polaris Mobile for the RX 7600M XT.

Where Each One Wins

The MI455X wins decisively in raw compute throughput. Its 157.3 TFLOPS FP32 performance is 7.8 times higher than the RX 7600M XT's 20.23 TFLOPS. Its 1,024 TMUs deliver 2,457.6 GTexel/s, which is 7.8 times the RX 7600M XT's 316.0 GTexel/s. The 432 GB HBM4 memory pool with 23.3 TB/s bandwidth provides 80.9 times the bandwidth of the RX 7600M XT, making the MI455X suitable for large-scale data center workloads such as AI training, scientific simulation, and high-performance computing where massive memory capacity and bandwidth are critical.

The RX 7600M XT wins in graphics-specific capabilities. It has 64 ROPs delivering 158.0 GPixel/s, while the MI455X has 0 ROPs and 0 MPixel/s pixel rate. The RX 7600M XT includes 32 ray tracing cores, which the MI455X lacks entirely. Full graphics API support including DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4 makes the RX 7600M XT functional for gaming and rendering workloads, whereas the MI455X has no API support.

Power efficiency strongly favors the RX 7600M XT. At 120 W TDP, the mobile GPU delivers 20.23 TFLOPS, which is 168.6 GFLOPS per watt. The MI455X at 2300 W TDP delivers 157.3 TFLOPS, which is 68.4 GFLOPS per watt, less than half the efficiency of the RX 7600M XT. The mobile part's compact IGP form factor and portable device dependent outputs make it suitable for laptops and mobile workstations, while the MI455X's EAM Module form factor targets server installations.

The RX 7600M XT also holds the advantage in production readiness. It is listed as Active with a 2023 release date, while the MI455X has no production status and a 2026 release date. The RX 7600M XT has recorded benchmark data across multiple tests, including a 13,907 G3D score and 7,140 GPU compute score, whereas the MI455X has no recorded benchmarks in the database.

The RX 7600M XT's nearest rival comparisons show competitive positioning. It sits within 0.9% of the NVIDIA GeForce GTX 590 and AMD Radeon Pro 455, and within 0.7% of the NVIDIA Tesla K20Xm. This indicates the mobile GPU delivers performance in line with older high-end desktop parts, though the MI455X's compute capabilities are in an entirely different performance class based on its architectural specifications.