AMD Instinct MI355X vs AMD Radeon RX 7900 GRE Comparison

FAQ

Q: What are the architectural generations of the AMD Instinct MI355X and the AMD Radeon RX 7900 GRE?

A: The AMD Instinct MI355X uses CDNA 4.0 architecture, while the AMD Radeon RX 7900 GRE uses RDNA 3.0 architecture. The MI355X belongs to the Instinct (MIx) generation, and the RX 7900 GRE belongs to the Navi III (RX 7000) generation.

Q: How much memory does each card have, and what type is it?

A: The AMD Instinct MI355X has 288 GB of HBM3e memory on an 8192-bit bus, delivering 8.19 TB/s bandwidth. The AMD Radeon RX 7900 GRE has 16 GB of GDDR6 memory on a 256-bit bus, delivering 576.0 GB/s bandwidth.

Q: What are the FP32 and FP16 compute figures for the two cards?

A: The MI355X delivers 78.64 TFLOPS for both FP32 and FP16 (1:1 ratio). The RX 7900 GRE delivers 45.98 TFLOPS FP32 and 91.96 TFLOPS FP16 (2:1 ratio).

Q: What is the process node and die size for each?

A: The MI355X is built on a 3 nm process with a 2380 mm² die and 185,000 million transistors. The RX 7900 GRE is built on a 5 nm process with a 529 mm² die and 57,700 million transistors.

Q: What is the power draw difference?

A: The MI355X has a TDP of 1400 W with a suggested PSU of 1800 W. The RX 7900 GRE has a TDP of 260 W with a suggested PSU of 600 W.

Q: Does the RX 7900 GRE have display outputs?

A: Yes, the RX 7900 GRE has 1x HDMI 2.1a, 2x DisplayPort 2.1, and 1x USB Type-C. The MI355X has no display outputs.

Where Each One Wins

The data splits cleanly by workload type. The AMD Instinct MI355X is the compute specialist. Its 16384 shading units, 1024 TMUs, and 78.64 TFLOPS FP32 throughput target dense mathematical workloads. The 288 GB HBM3e stack with 8.19 TB/s bandwidth provides massive data movement capacity, suited for large-scale inference or simulation tasks. The MI355X also holds an advantage in transistor count at 185,000 million versus 57,700 million, which contributes to its raw processing headroom.

The AMD Radeon RX 7900 GRE wins in graphics-oriented scenarios. It has 160 ROPs, an 80-core ray tracing array, and a pixel rate of 359.2 GPixel/s, none of which the MI355X possesses (0 ROPs, 0 MPixel/s pixel rate). The RX 7900 GRE also supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4, while the MI355X reports N/A for all graphics APIs. The RX 7900 GRE’s FP16 rate of 91.96 TFLOPS exceeds the MI355X’s 78.64 TFLOPS, indicating a potential edge in mixed-precision graphics workloads where FP16 is used for shading or post-processing.

Benchmark data exists only for the RX 7900 GRE. Its average benchmark score is 32456, with a percentile of 77 versus all GPUs. The MI355X has no recorded benchmarks, an average score of 0, and a percentile of 50. In the absence of head-to-head tests, the RX 7900 GRE’s measured performance in 3DMark Steel Nomad (4814), Geekbench OpenCL (175758), and Geekbench Vulkan (99850) confirms its graphics and general compute capability. The MI355X cannot be directly compared on those tests.

Architecture Differences

The MI355X uses CDNA 4.0, a compute-focused architecture with no graphics pipeline. It has no ROPs, no ray tracing cores, and no display outputs. The chip is labeled MI350 256CU, indicating a high compute unit count. The RX 7900 GRE uses RDNA 3.0 with a full graphics pipeline: 160 ROPs, 80 ray tracing cores, and a pixel rate of 359.2 GPixel/s.

The process nodes differ: the MI355X is on TSMC 3 nm, while the RX 7900 GRE is on TSMC 5 nm. The MI355X has a much larger die at 2380 mm² versus 529 mm². Transistor density is higher on the RX 7900 GRE at 109.1M per mm² versus 77.7M per mm² on the MI355X, but the MI355X has over three times the total transistor count.

Memory architecture is fundamentally different. The MI355X uses HBM3e with an 8192-bit bus and 8.19 TB/s bandwidth. The RX 7900 GRE uses GDDR6 with a 256-bit bus and 576.0 GB/s bandwidth. The MI355X’s memory bandwidth is over 14 times higher, which is critical for data-intensive compute but irrelevant for frame rendering.

Clock behavior also diverges. The MI355X has a base clock of 1000 MHz and boost of 2400 MHz. The RX 7900 GRE has a base of 1287 MHz, a game clock of 1880 MHz, and a boost of 2245 MHz. The RX 7900 GRE’s higher base clock suggests better sustained frequency in graphics workloads, while the MI355X’s higher boost ceiling supports burst compute.

The RX 7900 GRE supports PCIe 4.0 x16, while the MI355X uses PCIe 5.0 x16. The MI355X is an OAM module with no power connectors, the RX 7900 GRE is a dual-slot card with 2x 8-pin connectors.

Specification Differences

| Specification | AMD Instinct MI355X | AMD Radeon RX 7900 GRE |

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

| Architecture | CDNA 4.0 | RDNA 3.0 |

| Process Node | 3 nm | 5 nm |

| Transistors | 185,000 million | 57,700 million |

| Die Size | 2380 mm² | 529 mm² |

| Transistor Density | 77.7M / mm² | 109.1M / mm² |

| Base Clock | 1000 MHz | 1287 MHz |

| Boost Clock | 2400 MHz | 2245 MHz |

| Game Clock | None | 1880 MHz |

| Memory Size | 288 GB | 16 GB |

| Memory Type | HBM3e | GDDR6 |

| Memory Bus | 8192 bit | 256 bit |

| Memory Bandwidth | 8.19 TB/s | 576.0 GB/s |

| Shading Units | 16384 | 5120 |

| TMUs | 1024 | 320 |

| ROPs | 0 | 160 |

| RT Cores | None | 80 |

| Pixel Rate | 0 MPixel/s | 359.2 GPixel/s |

| Texture Rate | 2,457.6 GTexel/s | 718.4 GTexel/s |

| FP32 | 78.64 TFLOPS | 45.98 TFLOPS |

| FP16 | 78.64 TFLOPS (1:1) | 91.96 TFLOPS (2:1) |

| TDP | 1400 W | 260 W |

| Slot Width | OAM Module | Dual-slot |

| Power Connectors | None | 2x 8-pin |

| Suggested PSU | 1800 W | 600 W |

| Bus Interface | PCIe 5.0 x16 | PCIe 4.0 x16 |

| Display Outputs | No outputs | 1x HDMI 2.1a, 2x DisplayPort 2.1, 1x USB Type-C |

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

| OpenGL | N/A | 4.6 |

| Vulkan | N/A | 1.4 |

| Dimensions | 102 mm x 165 mm | 276 mm x 110 mm x 51 mm |

| Release Date | 2025-06-11 | 2023-07-26 |

Head-to-Head Benchmarks

No direct head-to-head benchmark results exist in the database for these two cards. The MI355X has zero recorded benchmark scores, while the RX 7900 GRE has ten. The RX 7900 GRE’s average benchmark score is 32456, and its percentile versus all GPUs is 77. The MI355X’s average score is 0, with a percentile of 50.

The RX 7900 GRE’s nearest rivals in the database are all AMD cards with similar average scores: the AMD FirePro S10000 at 32388 (0.2% delta), the AMD FirePro S9300 X2 at 32540 (-0.3% delta), the AMD Radeon RX 590 GME at 32601 (-0.4% delta), and the AMD Radeon Pro 570X at 32176 (0.9% delta). This cluster indicates that the RX 7900 GRE’s measured performance sits within a tight band of older compute-oriented cards, despite its modern RDNA 3.0 architecture.

For the RX 7900 GRE, the highest recorded score is in Geekbench OpenCL at 175758, followed by Geekbench Vulkan at 99850, and Passmark G3D at 27089. The lowest scores are in Passmark DirectX 12 at 107 and Passmark DirectX 10 at 139. The spread between OpenCL and DirectX scores shows the card’s compute strength relative to its graphics API performance.

The MI355X’s theoretical specifications suggest it would dominate in FP32 throughput: 78.64 TFLOPS versus 45.98 TFLOPS for the RX 7900 GRE, a 71% advantage. Texture rate is also higher on the MI355X at 2,457.6 GTexel/s versus 718.4 GTexel/s, a 3.4x difference. Memory bandwidth is 8.19 TB/s versus 576.0 GB/s, a 14.2x difference. However, the RX 7900 GRE counters with a 91.96 TFLOPS FP16 rate versus 78.64 TFLOPS, a 17% advantage in half-precision throughput.

The RX 7900 GRE has a higher base clock (1287 MHz versus 1000 MHz) and a higher transistor density (109.1M/mm² versus 77.7M/mm²). The MI355X has a higher boost clock (2400 MHz versus 2245 MHz) and a larger memory bus (8192 bit versus 256 bit). The MI355X’s power envelope is 1400 W versus 260 W for the RX 7900 GRE, reflecting the different design targets: compute throughput versus graphics efficiency.

The RX 7900 GRE’s release date is 2023-07-26, while the MI355X’s is 2025-06-11. The RX 7900 GRE has a launch MSRP of 549 USD. The MI355X has no launch MSRP listed. The RX 7900 GRE is marked as Active in production status, while the MI355X’s status is null.